Lars

It probably is a good idea to leave that header in there. It’s a signature that Avast has scanned the email. Any space it is taking up is not material. If on the other hand, it is material, than reducing the header size of your messages is not going to relieve you of an existing problem on running out of room on your hard drive.

Most of the information in a hidden header is meaningless and a waste of space but not the Antivirus header. It is one of the most important header lines in your message.

Nevertheless, there is no setting to disable the header information that I am aware of.

I don’t scan outgoing mail.