Huge Traffic Usage through Mail App

we are using the Mail App in our Self-Hosted Nextcloud-Instanz.
Since this point I regnoize a huge amount of traffic going to the imap server of our Mail provider.
The traffic was initated from the application server from my nextcloud, so i would believe it has to do with the mail app.

How frequently establish the mail app a new connection?

Currently I speak about 2 Postboxes connected with IMAP and an traffic per month from about 960GB.
Only for the IMAP Sync, Nextcloud Sync isn’t included there.

So is there any way to reduze this? Or configure the sync intervall?


We create an index of the user mailboxes for quicker access. Subscribe to Lazy and partial message cache · Issue #7770 · nextcloud/mail · GitHub to learn more.