GMail and POP3 RETR problem - switch to IMAP?

Question

When I'm accessing GMail inbox using POP3 protocol, it seems that after fetching given email using RETR command, after QUIT-ting and reconnecting, previously RETR-ieved email is not listed anymore when calling LIST.

Then, after going to: GMail settings//Forwarding and POP/IMAP and setting "Enable POP for all mail (even mail that's already been downloaded)", on next login all emails are being LIST-ed again, but if I RETR any of them, it again disappears from LIST after re-logging..

I can then go to GMail settings again and repeat the whole process, but it's a show-stopper for me as I'm writing a script that should work without any manual actions.

Am I missing something, or only IMAP can help here?

(EDIT: RFC http://www.ietf.org/rfc/rfc1939.txt doesn't say a word about RETR command deleting messages)

Answer 1

This is intended behaviour of Gmail. According to this question, "[a]ll messages may be downloaded to another computer once; after downloading mail, it will not download again."

There's also a 'recent mode', in which the last 30 days of mail are fetched, regardless of whether it's been sent to another POP client already.

That said, don't try to fetch all your mail by different computer in a short period of time, as Gmail may block your account for 24 hours.

I strongly suggest using IMAP.

Answer 2

Gmail’s POP3 configuration maybe sometimes confusing. You can find Gmail POP3 behavior here.

Switching to IMAP is very good solution.