Blocked outgoing email with doc-file

Viruses and worms
1

I have Avast Mac Security 2016 installed since last year, on both computers.

Today I got a block-warning in the top right corner of the screen.
It said that one of my outgoing mail messages (using Apple Mail) was blocked because it contained a doc-file with the name beginning with Scan_0041…

I replied to an email two days ago but I did of course not attach any doc-file. At that time I got no warning. The warning popped up today. After this I contacted the recipient to see if my reply had a doc-file attached. She has not replied yet.
I also made a full system scan but Avast found no infected files.

What does this mean? What do I have to do?

2
What does this mean? What do I have to do?
A screenshot of the message would help, so we see all info given by avast
3

She replied and she did not have the doc-file attached.

But today I got two more warnings about the same file - one for an incoming message and one for an outgoing message.
Both were sent/received today. And I have now linked to a screenshot with some personal info deleted.
I replaced my email address with “Me”
Image file with report here: https://uploadpie.com/kJEjJA

I have also downloaded and scanned my computer with ClamXav, but no infected files found

4

check mail account from webmail and delete mail

5

Ok, thanks
I thought about that too. But my impression is that there is some virus already working on my computer, that adds the doc-file to outgoing messages. Or how could it have ended up in the message I sent? Or at least… why did Avast send a warning about my outgoing message, saying that the file was attached?

6

Not sure, could be a sync bug with your mail app and avast

Anyway try to find it in webmail and delete and see if that makes any difference

7

The problem disappeared by itself. Avast is no longer sending any warnings