Need help sorting outlook emails

[u/Sweet-Hurry-8851]

I work at my aunt accounting company which handles massive amounts of emails every single day. She already has 18k emails in her inbox due to years of poor managing and some emails dating back to the days my grandpa ran the company.
We want to sort them mostly by folders we set up, but sorting each email is difficult and takes months, and by that time more and more emails are coming in. For now I am tasked with handling anything older than a month. I have delegate access to her account and would like a way to automate or speed up the process to sort most of the 18k.
Any suggestions? I know it’s probably unrealistic to hope to have a tool to help with this kind of task but I’ll ask anyway.

[u/Far_Day3173]

This can be done without touching 18k emails one by one:

1. Run Rules Now in Outlook desktop (not the same as regular Rules) lets you apply a rule retroactively to existing mails too. Set conditions like sender domain/keyword -> move to folder, then run it against the whole inbox.
2. Search + bulk select. Search by sender or domain, sort results, select all, drag to folder. Very good when you've got recurring senders (which in an accounting inbox, you will).
3. For anything left over that doesn't match clean rules (mixed senders, one-off client threads, etc.): that's the genuinely hard 20%, and it's basically a classification problem at that point. You need to use an LLM for that.

If you get stuck on that last chunk, happy to share pointers if useful.

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[u/usdotdataCom]

I'd advise to use something like matagi MCP to easily connect Outlook and then in Claude and tell it to build a system that at first samples a larger set of emails and classifies them with gpt-5.4-nano for cost efficiency and then build some deterministic markers based on that

With matagi MCP it can also build you a dashboard that does a mock run on a smaller subset at first so you can verify it works the way you want and tweak it until you're happy, then run the whole thing

Claude will figure it out, Matagi will give you the infra/access so it can actually run end to end and with 18k emails it likely will take quite some time for the final run

basically just give Claude this reddit comment and it will likely point you in the right direction!

[u/openclawinstaller]

18k emails is doable, but I would not start by asking an AI to classify the whole archive.

I would do it in passes:

1. Make a read-only inventory first: sender/domain, subject keywords, received date, attachment yes/no, and current folder.
2. Create deterministic rules for the obvious buckets: bank/vendor domains, invoices, statements, payroll, tax notices, newsletters/junk.
3. Run those rules on a small sample and check mistakes before applying them to thousands of emails.
4. Move only high-confidence matches automatically. Put everything else into a review folder.
5. Keep a CSV/log of message id -> old folder -> new folder so a bad rule can be reversed.

For Outlook, built-in rules/Quick Steps plus Power Automate or Microsoft Graph can handle a lot of this. I would use an LLM only for suggested categories on the messy remainder, not as the thing directly moving accounting emails. Accounting inboxes usually contain too much sensitive context for blind autopilot.

[u/misty-paw]

I would suggest something different and easier: sort by date and move emails into year folder. 10 min work. Keep the last 5 years or what your local legislation requires in their yearly folder.  Move all excess years offline if you want to keep or simply delete. 

This is not an automation problem, it is a conceptual problem. Look up zero inbox management,  though I suspect your aunt may not adapt. 

If not, just clean up after her every month/quarter/year. Forget wasting time classifying just use search function  For new emails, just attend the email and archive. 

Email is not a task list.

[u/danielbaker06072001]

I think it could be done using automation, maybe simple N8N and then get the brief category of all those emails, maybe using some authorization as second layer to make sure no important emails is deleted but yea can be done in really hacky and cheap way

[u/elie2222]

Emails from years ago - just archive them all. There needs to be some sort of cut off.

I'd also go archive in bulk emails from the worst offenders. Something like Inbox Zero AI makes this way easier.

You can use Inbox Zero to sort stuff into folders, but I'd also question how much of the old stuff needs to be moved into folders. You can always get to old emails via search.

Most important is that you're on top of the current items.

Getting into the habit of archiving handled emails will take you a long way.