NBG6515 makes trouble when sending Emails with attachement(s)

Ullrich

My NBG6515 workes all fine, but last months many Emails with one ore more attachements are not sent. The error notice gives notice: Time Out...
I think that this is a problem caused by the NBG6515 because on other networks all runs fine.
I didn't change the configuration since starting the NBG6515 three years ago.
It is not related to a certain provider nor to a certain file format. The ymptom came up slightly, now it is nearly impossible to send a Email with 2  attachements. 
What could be the reason, where should I search for a solution?


#Home_Router_Dec_2019

Zyxel_Eric

Dear @Ullrich,

1. What is the firmware version of your NBG6515?
2. Can you share the related log on NBG6515?
3. Have you tried to reset the NBG6515? See any improvement?
4. What kind of E-mail service that you used? And is there any problem with received E-mail?
5. If this issue only happened in the E-mail, please check the settings of the bandwidth Management, please enable the Bandwidth Management, and raise the priority level of E-mail or change the bandwidth of E-mail service.
Please enter the GUI >> Expert Mode >> Configuration >> Management >> Bandwidth Management.

Hill

Hello @Ullrich,
I tested my NBG6515, but there is no problem about sent mail with the attachments. (Gmail and Outlook) What kind of files that you attached in mail? Does the problem happen on LAN or WLAN device?