Managing email across multiple devices

Factual Questions
1

Long story short: The ISP (an evil cable company) that provides my main email account has merged a bunch of legacy email domains into one place (the old domain’s, e.g. something like pituitary.com, are now part of the bigevil.com email server but the emails sent to/from the original pituitary.com will still go in and out normally using the legacy address). I have to change all my email client accounts/settings.

In order to continue receiving and sending email on my devices, I have to move from my current POP3 device accounts to IMAP and change my current email password to the password I use to access my overall bigevil.com website. I have three devices I get email on:

Windows 10 PC, ThunderBird client
Samsung G25 (Android), Samsung mail client
Windows 8.1( :astonished_face:) Surface Pro (Don’t worry, I’m migrating it to a new Windows 11 Surface Pro this week!), ThunderBird client

All my clients are up to date for the OS they are on.

I pretty much figured out how to set up the new IMAP accounts (can’t just change a POP3 client account to IMAP), but I’m worried about how the switch will affect retention and storage of my email.

I keep my “permanent” email on my Windows 10 PC (let’s just call it the Main Acct). I have emails in archive folders going back more than 10 years and my Inbox has thousands of emails going back at least 10 years. I generally don’t care what happens long term on my other two devices, I don’t bother archiving mails on either and just use them to work with immediate emails.

Before I make the switch, I’d like to understand how I can:

  1. Migrate the POP3 Inbox on my Main Acct to the new IMAP account without uploading thousands of emails going back years into my webmail (which only contains current emails I haven’t deleted from my Main Acct Inbox going back a couple of weeks, less than 300).

  2. Once set up, keep any deletion (accidental or otherwise) I do on my Surface Pro or Samsung from deleting emails on the web server (in case my Main Acct, where I want my ASOT* emails to reside, hasn’t downloaded them yet)

  3. Maybe (if it is possible) create a situation I had years ago on my Work devices: If I deleted emails on my Main office PC (Outlook) it automatically deleted the email on my Work phone (Outlook) but if I deleted an email on my Work phone, it didn’t delete the email on my Work computer. I’m pretty sure it’s not possible now with what I’m migrating too, but I thought I’d ask.

I’ve found instructions (mostly from Mozilla) on backing up my Thunderbird profile/email in the current account and I basically don’t care a lot about backing up the Samsung client (Verizon has conveniently hidden the Samsung Cloud from me, so it’s going to be a project backing those emails up). I’ve gotten the instructions on what settings I need for the IMAP client accounts, plus stern instructions to change my password on my ISP account (which will erase all trace of my current email account password) before setting the IMAP accounts up.

Any (factual) advice (that isn’t get IOS or Linux) is welcome because, frankly, I’m confused as to what the email retention deletion rules are in IMAP and what leeway I have in settings to manage retention/deletion.

*ASOT: Authoritative Source Of Truth (it’s a digital transformation thing)

2

Looks good, but you left off step 4:

  1. Stop using email from your ISP!

Being stuck with a crappy ISP when they keep jacking your rates because you can’t/won’t change your email address is a losing proposition.

IMAP should leave everything on the server up to your mailbox limit until you delete it.

3

So I think the main thing to keep in mind here is that IMAP is fundamentally different from POP3. With IMAP, the server is authoritative and whenever a client (any of your devices) does anything with a message, whether that’s replying to it, archiving it, or deleting it, it tells the server to do that and that action then gets synced across ALL your clients.

It’s kinda like accessing www.gmail.com from different devices… anything you do on one device happens on ALL devices, automatically, unavoidably (because it’s actually happening on the server, and your clients are just a reflection of the server).

So to get around that, you have to use a workaround: Thunderbird Local Folders:

The regular IMAP account folders are on the server. If you want to keep a message on a particular computer, you have to first move or copy it into a Local Folder. If you copy it there, it will be a local file on your computer and the IMAP server copy will be unaffected (meaning you can create Local Folders and local copies on more than one device). But if you move it there, you’ll have a local copy, but it will also be deleted from the IMAP server (and thus all your other clients).

As for your old POP3 mail, same thing… move/copy them all to a Local Folder. Don’t upload them to the IMAP server.

Make sure to back up your Local Folders, because those messages are only on that one device. If its drive dies, the messages are gone. It’s a lot safer to keep them on IMAP servers, generally speaking, and just put them into an “Archived” folder. Most email providers have much much better security and backup systems than your home computer.

Well… IMHO only, and probably not what you want to hear… but… tis simpler to just use a cloud-native email like Gmail or ProtonMail or Hotmail (or whatever it’s called these days, Outlook? Live? I forget) or Yahoo Mail or whatever and never have to think about Thunderbird or email protocols again. The cloud emails are super simple and don’t lose your emails (they encourage you to just archive everything forever).

If you insist on keeping your ISP email and having local copies on your devices, then you have to jump through hoops like the above. There’s a reason most of the world has moved to gmail.com and similar; there’s zero setup and zero hassle and zero config. IMAP, Thunderbird, etc., are artifacts from a previous era. Nothing wrong with them per se; you just have to be willing to do more work to keep using those technologies.

4

I manage my email pretty much exactly as described in the OP. I store all emails locally on my PC using Thunderbird, which accesses the server via IMAP. I also access the server from my phone via IMAP, currently also using Thunderbird although in the past I’ve used other mobile clients. On the PC, when I read and deal with an email in the inbox, I either delete it (if it’s spam or something else I don’t want to keep), or drag it to an appropriate local folder for permanent storage, which removes it from the server and stores it on the PC. Unless there’s a reason you’re wedded to the Samsung client, you may want to consider using Thunderbird on your phone. It’s very easy to set up Thunderbird on the phone if you already have it set up on your PC. But any email client on your phone should work ok.

The main difference from what you describe is I almost never delete emails via the phone. There’s no real reason to; when I delete or move the email from the inbox on the PC, it’s removed from the server so it no longer shows up on the phone. If you do delete an email on the phone, it will be deleted from the PC as well. The solution is just don’t do that.

I don’t think you need to do anything with your stored local mail when you switch from POP3 to IMAP. Once it’s stored on your PC in a Thunderbird folder, it doesn’t matter whether it was downloaded via POP3 or IMAP. It’s been decades since I switched from POP3 to IMAP so perhaps I’m not remembering something, but I’m pretty sure that when you switch to IMAP, all your local folders will remain untouched.

This is the same setup I’ve used for at least 30 years. In the past I’ve lost email due to server issues. I know that in the modern era I’m more likely to lose files stored on my PC than files stored on a well-maintained server, but I’m reluctant to change a system that has worked well for me for much of my life and continues to do so.

5

I think it’s all been good advice so far.

One very reasonable thing you can do in Thunderbird is set one of your devices (probably the PC) to download all messages. This will give you a local copy of all of your email, in the event you lose access to your ISP’s version.

The advantage of doing it like this, instead of copying all of the messages to your local account, is that Thunderbrid does it in the background, so you don’t need to worry about it. It will also sync changes you make on other devices.

The easiest thing to do with your old POP3 mail is to archive it on your PC. It’s there if you need it, but otherwise is not in your main account.

If you do not have a reliable backup plan for your PC, then I recommend that you do upload all of your old POP3 email to your ISP, space permitting. This has the advantage of giving you two copies, the one on the ISP’s server, and your local copy, and you will also be able to access all of your old email from your other devices.

This talk of ISP email is the first time it occurred to me, my new ISP did not offer me an email account. I just switched from Comcast to T-Mobile/Intrepid. I had a never used @comcast.net address, but I don’t have a new @t-mobile.com address.

6

If by “local folders” you mean custom folders that you’ve created and into which you move your emails, yes, that’s true, they won’t be affected. But switching from POP3 to IMAP or vice-versa will create a whole new account (in MS Office Outlook, and I’m pretty sure in any email client) with its own set of default folders (Inbox, Sent Items, etc).

Question for the crowd. Is it generally acknowledged that IMAP is the more modern, superior protocol compared to POP3? Microsoft apparently thought so when they released MS Office 2021, whose version of Outlook supports Oauth 2.0 only with IMAP and not POP3. FWIW, Thunderbird supports Oauth 2.0 with either one.

7

Absolutely. POP3 is a terrible, inflexible protocol that’s been basically obsolete for 20 years or more. There’s no reason anyone should be using POP3 if IMAP is available.

8

Thanks. When I was recently helping a friend set up a new business computer for their home office, the choice was to set up Outlook with IMAP and Oauth 2.0, or set it up as in Ye Olde Tymes with POP3 and lowered security in Gmail so that an app-specific password could be used in place of Oauth. I guess we made the right choice!

9

IMAP presents the paradigm that all of your devices are caches. Which is the reality. You should plan on any device you own suddenly disintegrating with a total loss of data.

The question of resilience however should not be left with your ISP or mail provider. In the modern world they are not to be trusted to preserve your data. So the IMAP service is a nice way of all your devices agreeing on what your email status is. But anything you value, you archive separate to the email system. And do so in a resilient manner that is independent of any particular device. That is more effort. The various cloud storage systems is one answer. They also get you consistent views across your devices, again providing the device as cache model.

POP was a horrible protocol because it really gives you the worst of all worlds. It made sense when it was designed. That was a very different time.

IMAP gives you a clear abstraction, one that is clear about what it doesn’t do for you. Don’t trust the server with the only copy of important emails. IMAP isn’t a backup or archive service, and treating it as one may not end well.

10

Thanks everyone for your input. In my defense, this email account was originally with an actual ISP, which I believe I accessed through dial-up! POP3 was definitely the way to go 20+ years ago. The original ISP was swallowed by a cable company, which was swallowed by another cable company, which was swallowed by the cable company that now provides (among other things) my internet and email. In the 20+ years I’ve had the email, it is the one I use for sign in and contact with a variety of websites. I’ve seen too many OPs on this site about how to do a password reset when the email doesn’t exist anymore to move quickly to shut this one down.

I checked my Thunderbird profiles folder and it is only 10 GB (I literally have 3-5 K messages depending on how you count my deleted folder). The good news is my webmail is using only 0.02 GB (I only have 85 messages- the server seems to delete messages when they are read on my PC TB). The bad news is that my webmail has a maximum storage of 5 GB, so if I create an IMAP account and then try to port all my Inbox messages (and at least some of my Sent folder) over, I think maybe something bad will happen.

My plan, partially based on what I learned in this thread, is to:

  1. Move all my Inbox email received prior to January 2025 into a new TB Local folder (I have a dozen Local Folders in different categories but I don’t have the time to sort and move a couple thousand messages. Maybe later). Delete all the messages in my Sent folder prior to the same date. Delete all the messages prior to the start of this year in my Trash folder (am I the only one that has to occasionally root through this folder when someone asks if I got their email?).

  2. Back up my TB profile folder (10 GB won’t take that long)

  3. Turn off POP3 downloading on my current accounts- phone, PC, Surface Pro

  4. Change my account password for my ISP (removing all access from my current POP3 accounts)

  5. Create a new IMAP account in TB on my PC

  6. Move my TB POP3 Inbox and Sent contents (skinnied down) into my IMAP account

  7. Move my TB POP3 Local Folders into my IMAP account

  8. Create a new IMAP account on my phone, ignore the current Surface Pro, I’ll just have a new instantiation of TB on my new Surface Pro when I get it running this weekend.

  9. Figure out how to move my Sent messages on my phone’s Samsung email client into my new IMAP account (not helped by Verizon hiding Samsung Cloud on my phone).

  10. Profit???

Any advice on pitfalls or things I’m neglecting are welcome.

11

Hmm. Strongly disagree with this. POP has its warts, but IMAP does too. And is poorly supported by many clients, which isn’t its fault, of course, but suggests that the demand isn’t there. And if it’s clearly better, I’d think the demand WOULD be there.

Can you elaborate?

Oops: thought this was quoting, I’m referring to the post saying POP is obsolete and everyone should use IMAP.

12

Yeah, I was thinking POP3 went out of vogue decades ago.

I mean, I can’t think of the last time I had an email client that actually downloaded the email from the server and managed it locally. It was probably in the 2001-2002 timeframe somewhere.

This. Come on folks; you’ve got to keep up with the technological times, not try to whip and beat Windows XP into continuing to work, or how to manage POP3 mail in 2026.

13

Honestly, they’re both kinda obsolete. Most people just use Gmail or iCloud mail or similar now, which have their own apps and protocols. The days of using Thunderbird or Eudora or Outlook to fetch email from your ISP’s mail server is mostly for the older folks who’ve just kinda stuck with that practice out of habit (like many on the SDMB, I presume).

I don’t mean this as any sort of value judgment, just an observation that (as with so much else) email usage patterns have changed a lot over time and the younger generations mostly don’t do these things anymore.

POP3 is especially obsolete because it doesn’t support multi-device usage and sync very well, which wasn’t a big deal before the 2010s or so. But as soon as everyone got smartphones, being able to utilize the same inbox seamlessly across two or more devices became an everyday necessity for a lot of folks. Many ISPs and webmail services don’t even offer POP3 anymore.

IMAP is more modern in that it natively supports multiple devices to some degree, but it’s still not as seamless as just using a cloud email and its ability to sync not just basic folders, but labels, filters, snoozes, reminders, autocomplete, setting, etc. Email just got a lot more powerful than those older protocols supported and nowadays it takes specialized apps and protocols (that each proprietary provider makes) to give you that sort of same experience across all your devices.

This is doubly the case when you’re on a same-provider system, like Gmail on Android or iCloud on iPhone. You don’t even set up separate accounts or servers, you just log in with your everything account and your emails are just automatically there the same as your photos and files and such. It’s not really considered a separate service anymore, just part of the standard package alongside all the other personal cloud stuff people use. They’ve abstracted away all the servers, protocols, clients, etc.

And besides, email itself is relatively obsolete as well outside of business contexts. For personal use, most people now use texts, IMs, Discord, etc.

Again, not a value judgment. Technology and habits have just changed a lot, and many things become obsolete quickly.

And if there’s still a client that doesn’t support IMAP (is there?!), THAT client itself is obsolete. POP3 is in its death throes. IMAP isn’t far behind.

14

I don’t know what your ultimate goal here is (like why do you need to move your skinned down POP3 into your IMAP?)… but I don’t think it has to be that complicated. Just follow these simple rules:

  • Delete anything you don’t care about
  • Put everything you want to keep safe (for archival) into your local folders, and remember to back those up regularly
  • Everything else can just live in the cloud, in your IMAP folder. You don’t really need to worry about backing the whole thing up, just copy individual messages you really care about into your local folders — if you must. It’s highly unlikely your ISP will lose your emails anyway, as long as you remain a paying customer.

Or, when you can, just move to a cloud email and never worry about this stuff again. It’s not worth the time and mental energy to worry about any of it. Like literal hundreds of millions of people never worry about any of this anymore because they’re just not using the old technologies anymore.

15

Slight side-topic; are non-Google, non-Apple, non-Microsoft cloud email providers still relevant and reliable these days? Yahoo for example.

I’ve been using Gmail for years but I don’t love it; it works, and that’s job-one, but I find their clients clunky. And I have a lovely Yahoo email address, but unsure if I can depend on them.

16

Reliable? Well, I haven’t heard of any major email disasters from the other smaller providers recently, but it’s also not something I keep close track of. And popular, probably not, when big providers do the job so well already.

I do know there ARE still alternatives, like Yahoo is still popular in Asia, ProtonMail is for people who care more about privacy, Fastmail is another option, Hey.com was briefly interesting for a second or so, I think Zoho is more popular in India, etc.

A lot of businesses and schools also use whitelabeled Google or Microsoft mail, but with their own domain names.

It’s really rare for major email providers to just disappear. Usually they get bought out and you have some time to either transition to another email account, or pay money and keep yours, or at least download your messages.

I still have my Hotmail account from the Windows 98 days, for example, and it serves as my Microsoft account in lieu of a outlook.com address.

And Yahoo is still relevant in Asia (for some reason) so will probably be around for a while. I wouldn’t be surprised if the US portion got sold though. In fact they’re now owned by some private equity-ish firm.

Hilariously, they tried to buy Chrome (the browser) in 2025: Yahoo wants to buy Chrome | The Verge Definitely not a headline I would’ve ever expected to see.

17

Hm. I resemble that!

Srsly, I might not be typical, but I POP mail on multiple devices on a dozen or so accounts, using Outlook on PC and Aqua Mail on phone.

Webmail for that would be a LOT more work, having to manage multiple accounts in separate browsers, or at least separate windows. As it is, I have one set of filters/rules and one canonical machine, whose mailstore gets backed up nightly. For me, IMAP would be more painful: one of the beauties of multiple devices is that I get multiple “cracks” at the same email, so if I miss something, I usually (!) notice it on another device.

For OP: As others have suggested, letting your ISP manage your mailboxes is usually a mistake. At a minimum, it means big fun when you move (or they change). Buy a domain, use those addresses, even if your domain provider doesn’t manage your actual mailboxes. I’m partial to EasyDNS.ca because they provide unlimited forwards, including wildcards, and also do SRS header rewrites, which means that you can use random email addresses @yourdomain and it Just Works. Been doing this for 20+ years and it solves lots of problems, including making spam easier to identify. To wit: if I get spam “from” Bank of America and it’s not addressed to bankofamerica@mydomain, I know instantly that it’s not legit. Or I would if I used BofA.

Anyway, I appreciate the thoughtful reply. I suspect it’s that we have different usage patterns.

18

If you know what you’re doing and you like it that way, by all means, keep doing it as long as you’re able to! It’s just not a typical usage pattern (anymore), but so what? Do what works for you :slight_smile:

It’s not so much what I personally do or don’t, just what the big providers have moved to, and with them, their consumers. With the advent of iPhones and Androids, especially, Apple and Google ate the business of a lot of traditional services, not just ISP emails but also things like Dropbox, Photobucket, etc. Their “good enough” integrated services made it much harder for standalone providers to survive.

Microsoft tried the same thing and failed miserably with Windows Phone, but at least they have a corporate foothold (in terms of bundled Outlook.com email and calendaring, etc.)

Like it’s not really even just about email, but how “personal computing” as a concept has largely gone from “a PC you own, with various apps you buy” to “buy one phone and pay the same company for a monthly subscription for everything you need”. We’ve gone from a DIY hacker ethos to a mindless consumer one.

Personally speaking, I ran my own mail servers as a kid when I thought that was super cool and nerdy. But an adult I just don’t have as many hours or fucks left to give, so it’s down to the one ol’ boring Gmail :sweat_smile:

19

My long-term email (30 years!) is just that: my own domain on my own server. But nowadays I just pull from it within GMail (or now, I forward to my GMail account, now that GMail is stopping POP support).

20

The Wikipedia article about POP has a section comparing POP with IMAP that lists some of POP’s limitations.