Text-only emails are no problem. Emails with even small (eg 3-4MB photos) attachments sit in Outbox and never appear in Sent box. But they have been sent (even though I’ve had no indication that they’ve gone) and, in fact, many times (between 3 and 20 times) over. Some colleagues are becoming increasingly annoyed that I haven’t done anything to stop this. I have set the synching interval at 30mins to give plenty of time for the mails to be sent, so that the computer shouldn’t try repeatedly to send them, but they still get sent over and over again.
Your server is not sending the correct response once the message has been sent, therefor eM Client will send it again and again, until it gets the OK from the server. Go to Menu > Tools > Operations and look for any SMTP errors in the Log tab.
To stop the messages being sent again, delete them from the Outbox.
Did anyone find out how to correct this? I am having the same problem: colleagues receiving several emails from me without the email ever showing as sent. I asked my internet provider, but there isn’t any problem on the server. They said that it is mostly likely the email client.
Yes agree with @Gary this is normally some server SMTP related issue and nothing to do with eM Client. Needs operations logs to determine the problem.
The only other things locally that can sometimes interfere with outgoing mail where the recipient gets multiple emails is eg: if you have some sort of trojan virus or malware on your computer, where emails seem to get stuck in the Outbox folder, but it is actually being sent to the recipient. So, the recipient gets multiple copies of the same email. So scan your computer for Viruses and Malware. I’ve seen this happen before in Outlook on friends computers so might be same problem if your SMTP server is ok.
Lastly if you have an IMAP, Exchange or iCloud acct you could also try removing your account in eM Client and re-adding it back in again.