Unable to send email, stuck in outbox
I recently encountered issues with using posteo.de and email aliases (not necessarily related), all stemming from timeout errors. The effects range from unable to save sent mail, and hence being stuck in the outfolder, to not sending emails at all and thus being stuck in the out folder, to being unable to connect and working offline.
Setup:
posteo.de - email alias to ahoi.io gapps - work stuff, no alias
I'd be happy to sponsor a year of posteo to get this sorted.