My ISP has problems with their outgoing mail server, resulting in a significant portion of my outgoing emails being discarded on a more or less random basis. I'm using IMAP.
I also have another account with a different ISP. If I were still using good old POP3, I could use the second ISP's SMTP server as the outgoing mail server for both accounts, and use the first only for incoming mail.
Is this possible at all with IMAP? And if so, how do I set it up in Mozilla Thunderbird? (Google has failed to enlighten me!)