If I send an e-mail with exp. size=28727079 the eM Client resends the e-mail and recipient receives inifite the same e-mails.
The e-mail is still in Outbox folder. The time to process e-mail by the server is around 60 seconds.
Send immediately is unticked and synchronization set to 3 minutes in settings.
I think this is a big issue in eM Client to prevent sending big messages.
I’m an administrator of the mail server, so It’s not an issue set exp. 100 MB message size. As I remember the error was time out or something like this. The issue was OpenDKIM software. It took a lot fo time to sign such big e-mail and eM Client didn’t know how to handle such situation. MS Outlook has got time out up tp 10 minutes in settings.
Anyway I’ve changed OpenDKIM to another software and the problem disappeared.