POP on Dell - XP to IMAP on Dell/Mac

Friend is still using a Dell running XP. Mostly just for email now. Setup is POP/SMTP. Thousands of emails.

Any suggestions as to how best to go about getting all his emails on the Dell over to Mac (High Sierra I think) and then switch the Dell to imap as well?

He will probably still want to use the Dell but sometimes it gets clunky so at least he can then switch to the Mac and continue.

He is paranoiac about losing any emails so safety is paramount.

Appreciate advice.

Are you using Outlook on the Windows XP box? Is the mail being stored in a .PST file? Google for one of the many Windows utilities that will let you convert a .PST file to an .mbox file. The conversion process should produce an .mbox file you can move to the Mac and leave the mail on your XP unchanged. Apple Mail can import .mbox files. So can handy Mac programs like EagleFiler that let you search and view old emails without junking up your current email.

(Possible wrinkles. You’re not using Outlook. XP may be old enough to pre-date .PST email storage. File formats may have changed over the years.)

It is not that difficult, but could take some time.
The Mails on the Dell are stored locally.
So setup the Mail-Account on both, the Dell and the Mac as IMAP.
Then move the Mails from the local Files to the IMAP Account on the Dell, and just wait, until everything has been finished.

This requires of course, that the Storage capability of the IMAP-Account is large enough, to hold all those Mails.
If not, do it the same way, but remove the Mails again from the IMAP-Account into local Folders onto the Mac, to free space again, and then continue this, until everything has a copy on the Mac.
In this case, you only copy the files on the Dell into the IMAP, and not move them without keeping a local copy.

Thanks guys - both look useful.