I wrote this earlier. I am a sysadmin and do devops. I just spent 7 days writing what seems like a trivial endeavour with LLM, a wrapper around imapsync to migrate terabytes of email from an onprem server to exchange online. opus5.5 would have broken the exchange mailboxes at least four times.

there exist dedicated email migration software, it's pretty expensive, it was worth it for me to spend the time to learn things about how MAPI, IMAP and different email clients and different email servers handle things, their quirks and edge cases.

Before LLM it would have taken me months, not 7 days, to produce what I did, so the calculus would have skewed towards either buying the email migration software or other subpar solutions, accepting a lot more errors and losses during the migration to be handled with a different process.

With LLM it made sense for me to spend this time and, as I said, I learned quite a lot about emails.