Mail with attachment cannot be successfully sent out

Hi Sir,

I was having a pro license but it just had been expired, hope I can still get help from here.

I’ve used eM Client for about 2 years, it works just fine for a long time. But recently I found some of my mails with attachment haven’t been sent by eM Client, the mail just “disappeared” after clicking the send bottom, it is even more annoying that there is no way to confirm whether my mail had been successfully sent or not.

After some tests, I can found error message as below

Also I noticed that the problem only happens when there is an attachment in the mail, I had tested to send a mail attaching a 1MB size powerpoint file and the problem was the same, so file size is not the problem.
I am using G-Suite as my mail provider, and if I do the same thing on Chrome web browser (gmail web interface), any mail with attachment of any size can be successfully sent out, so I may conclude there is something wrong with eM Client.

my eM Client version is 8.2.1659 (845a639), and SMTP setting is

  • Host : smtp.gmail.com
  • Port : 587
  • Security policy : Force usage of SSL/TLS

I am using Windows 10 without any anti-virus software.

checked some topics related to this issue but cannot figure out the solution
(actually I checked many topics but here I can only paste one due to I am a new user in this forum)

any suggestion would be very appreciated, thanks.

As you have the correct Gmail SMTP settings and no optional antivirus program running, I would next suggest to remove your Gmail account from eM Client and re-add and see if that fixes it.

Note:- Before removing the acct, backup eM Client first via “Menu / Backup”.

thanks Cyberzork

I had removed then re-add my Gmail account, I’ve got the same error message (this could be caused by temporary server unavailability …), but the mails can be successfully sent out in this case, I am not fully sure whether the problem is solved or not but really appreciated for our suggestion.

one thing to be noted, the mails which were considered not being sent previously, were actually sent out after a long time(?), I tried to sent out many mails yesterday, those mails did not got to outbox at that time after pressing the send bottom, so I though they were “disappeared”. However, after may be 24 hours, I just found they are in the outbox, it seems there is a huge delay(maybe more than a day) from sending the mail to the mail can be seem in the outbox, not really know whether the problem belongs to eM Client or Gmail, thanks.

I tried to sent out many mails yesterday, those mails did not got to outbox at that time after pressing the send bottom, so I though they were “disappeared”. However, after may be 24 hours, I just found they are in the outbox, it seems there is a huge delay(maybe more than a day) from sending the mail to the mail can be seem in the outbox.

That is very unusual that when you press send (with any attachment size) the email doesn’t appear in the outbox within a few secs. Emails with attachments can take time to send from the outbox (depending on the size of the attachment), but to not go in the outbox straight away when you press send is very strange.

I’ve personally never seen that issue with that same version of eM Client & Gmail. Hopefully someone else on this forum can help you.