Hi everyone! We're facing a frustrating issue with our mail flow. Some of our users are experiencing a problem where their emails are being sent repeatedly—like thousands of times! It usually happens with larger attachments sent to over 50 recipients. We've already checked our connectors, which include inbound, outbound, and archive, and we've done a thorough check for any viruses or suspicious activity on the users' accounts. The recipients are all individual addresses, not groups. Any advice on how to resolve this would be greatly appreciated; we're really at our wits' end!
1 Answer
It sounds like you might be dealing with a timeout loop issue. When you send large attachments to a bunch of recipients, the mail takes longer to process. If there’s a delay in acknowledgment between Exchange Online and Hornet, it will retake the send like it's fresh. I recommend checking the timeout settings on your Hornet connector. We had a similar problem when our security appliance was scanning large files too slowly, causing Exchange Online to think the delivery failed and retry it. So definitely up the timeout threshold and maybe limit the message sizes to prevent this from happening in the first place!
I just ran into a similar problem, and I noticed that while Hornet shows every resend, Exchange only shows some. Have you found any way to increase those timeouts?