How do I move 15 years of email to a safe and accessible archive? Should I even bother?

I have 20+ years of emails, both professional and personal. For archival purposes and to make my email program leaner and search faster, I want to export 15 years worth of emails (with any attachments) elsewhere and delete them from the Mail app and the corresponding Google and iCloud servers.

  1. Should I bother or am I creating unnecessary work for myself?
  2. Should I export the emails to something like DEVONthink or do you recommend something else? If DEVONthink, how do I select and export emails (with attachments) from a specified date range, e.g, from 2015 and older?

Any guidance will be appreciated!


Ok, <cracks knuckles> there’s several answers to this question, and it depends on your comfort level with progressively more complicated technology.

  1. If you already have DEVONthink, that’s probably the right answer. DT works with a plugin for the Mail app to archive mailboxes, saving each email as a .eml file.

  2. Eagle Filer also has excellent support for archiving mail from the Mail app. If you already have a license, again this is probably the right choice.

  3. You can right-click on a mailbox in Mail and choose “Export”, which will save the mailbox in the industry-standard mbox format.

  4. If you really want to get technical and don’t mind some work on the terminal, you can install a command-line app like mutt or offlineimap that can automatically download your mail using pop3 or imap and create/update mbox archives of it. This will probably require you to setup credentials specifically for the application for whatever email service you use.

All that being said, personally, I don’t even worry about it. If the email providers I use ever have an issue and I lose all my email… oh well. I make a backup (in DEVONthink or just in the Finder) every now and then, maybe once a year or so. Otherwise, I don’t bother.


I am using Horcrux for email backup:

It also can be used to create mbox archives:

I have not done that so far. Horcrux works just great. Also for migration, for restoring and what not.

If I have very important emails, I will save them as PDFs. This does not happen very often.

I am fine with just using IMAP and IMAP folders. Stuff gets being filed in those folders (or deleted) in order to have an empty inbox after having dealt with it. I have about 20 years of emails in those folders. If I ever will get to the conclusion that I have to delete emails, I will do so in those folders.

Devonthink has its own routine for that.
You could find details within the “Help” of DT3.
The function is “hidden” behind the “Import” function, on top of the left column with you Groups.

Depending on how many Mails you got during those 15years, it could also be a contribution to a much better performance of Apple Mail, to reduce the amount of Mails stored inside the App.

I use mailarchiver x

I never delete any mail from the server that I may need in the future and have messages going back to 12/2005. I do export my mail on a regular basis as a backup.

You can export any or all of your Google data at You can even schedule Google to to do it automatically every 60 days.

I have about that much old email in DT (a few Google Takeouts and .mbox from Hey) and it’s been solid. Very rarely have I even felt the need to double-check a search on the email services themselves.

I did this last September as I had a crazy amount of personal emails that I didn’t need. I exported to DEVONthink using the plugin, and I had no issues. I found searching the database flawless, and it has hit the right result every time. I also noticed my email app is considerably faster, especially when searching.


I would personally use EagleFiler instead of DEVONthink but just because I’m not using DEVONthink for anything else these days. If you are comfortable with DEVON there is no need to add another tool. Just import your mail archive and let DEVON work its magic. I would suggest using a separate DEVON library just for the mail archive so it’s easy to backup and manage everything in one go.

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Sure, with just 50.000+ Mails from 19 years, you are using E-Mail not so often obviously, and Mail could handle those amounts easily.
My recommendation regarding the performance was for People who are heavy Mail User… :wink:



I have years of .dbx files back when I used Outlook Express in the early 2000s. I am trying to figure out how to get some of that stuff into something readable along with saving the attachments.

It would be great if they became searchable with DevonThink

I stumbled upon this last night. How do you like it? Any drawbacks or things to look out for?

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Do you have Outlook available?
If yes, you should be able to import those files there. Thereafter you could either use an IMAP-Account to transfer the Mails from Outlook into Mail, or you could Export the Mails from Outlook again, using the .pst format.
You should be able, to import .pst thereafter into Mail, and from there via the PlugIn into DT3
If you do not have Outlook available, you could use one of the many “.dbx to .mbox (or .pst!) converter” available on the internet, to transfer the .dbx into .mbox/.pst again, and to import them into Mail.
The .mbox format could also be directly imported into Devonthink, via the "import → UNIX-Mailboxes.

I’ve been using it for 3 years and have found it reliable.
There are two archives set up one for me and the other for my better half, it’s scheduled to download each Monday from our respective gmail accounts.
Prior to that I imported nearly 20 years worth of emails from various other accounts and there’s close to 500,000 emails archived.
Loading and searching is quick.
There has been the odd issue, but the developer is very quick to respond and has resolved issues.

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Thanks everyone for the helpful advice and feedback. I’ll consider the options offered—much appreciated!

I have some 85K emails in Devonthink. However the database took too long to load so I created databases that covered 5 years of emails. However, this didn’t really help as if I needed to search all email I had to open all databases. I often couldn’t exactly remember which 5 year block an email was in.

The, “took too long to load”, it’s probably due to a 2015 imac.

It’s worth noting that Devonthink stores emails as separate eml files. Eagle filer stores them as mbox, if more than one email is imported at a time. mbox means less individual files so faster loading. However if an mbox file get corrupted you may lose a whole lot of emails.

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I don’t have any new details to add, in terms of tools and techniques.

But I can +1 to using EagleFiler for email archives. I offloaded ~50K email messages in 2020, and EagleFiler has handled the occasional searching or archive perusal use cases I’ve had since.

My archives go back to 1995, and span Eudora, Outlook (Windows), and clients.

I don’t remember the full processes I used for the foreign clients. I believe I had already imported the Eudora mail into, and thence to EagleFiler. The Outlook archives I know went through a converter utility (which one, I can’t say), and then (I think) directly into EagleFiler.

How to I reactivate/reinstall the Mail extension for DT? It shows installed but it is not in Apple Mail? I want to move years of emails to DT to archive.

This covered sooooo many times on the DEVONthink Forum where I think you should be discussing all this (or searching past posts on just this topic), or look in the “DEVONthink Manual”. Even says that on your screen shot. :wink:

I it NOT an extension. It’s a “plug-in” on Mail’s General tab, bottom left corner.

Difference between a “plug-in” and “extension”? I haven’t the foggiest. :wink:

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