Comment 4 for bug 741506

I've founded reason of problem.
In get_mails function: "if rec.last_mail_id < int(msg_count[0]):".
If I delete mail from my mailbox (not in poweremail, but in my mail client) msg_count[0] reduces by one. Now next incoming message will not be received because of upper "if" condition.
It would be nice to have another method of finding new mails.