https://marketdental.com/ Posted by Cătălin on Mon, 24 Apr 2017
Outlook seems to hit a problem when sending large emails. If an email sending takes too long (slow network, large attachments, etc) then outlook seems to assume it failed and will try to send the email again. However, the original email is still sending. This process repeats, causing the same email to be sent multiple times. Whilst stuck in the loop, any subsequent emails sent, even if they aren’t large, will also get caught up and get sent.
The solution is to extend the amount of time Outlook will wait until it deems the sending to have failed. The default is 1 minute, so extending this to 5mins should do the trick (although under normal circumstances, of course, if an email is so large it takes longer than 5 minutes, it probably shouldn’t be sent via email).
Follow this steps to increase the server ‘Server Timeouts’ period: