Block Mail Attachments troubleshoot
Liêm
Newbie ✭
Hi Admin;
I need to your support. we have problem with email. we cannot sent the email if have attachments files. But i can sent with have not the files attachmens.
The firewall has been factory default configuration by me but the problem has not resolve. when i bypass the firewall, i can sent email with attachments . so, i need your support
Thanks you!
Category: Email Security Appliances
0
Answers
You have to check the System Log (Monitor > Logs > System Log) to see what's going on. The screenshots you provided are useless?
I second what @Simon_Weel wrote about the screenshots, not much to see there.
If you're able to send mails without attachment (small) but not with attachment (large) it might be related to a MTU issue on your WAN Interface. Make sure the MTU fits to your internet connection, e.g. 1492 for PPPoE etc.
This might give you an idea what to do:
https://www.sonicwall.com/support/knowledge-base/how-can-i-determine-the-mtu-size-of-wan-interfaces-manually/170504812146650
—Michael@BWC
this is inform when i sent the email with attachments.
I have been check, The firewall has factory default configuration.
@Liêm I'am confused, you're talking about sending mails but the screenshot shows web traffic. To clear things up, are you using some kind of Webmail (OWA) or is it Outlook sending to an Exchange Server?
If you're certain that your MTU is correct we can rule that out. Maybe double check with ping to see when it starts to fragment.
—Michael@BWC