Essential Email files being blocked

I continually receive invitations to bid from trusted email sources with attached files photos of the bid subject being blocked. How do I correct this?

How do I correct this?
that depends on what the block message say

Hi,

Is the issue similar to this https://forum.avast.com/index.php?topic=285835
If not, please provide a screenshot of the detection message from Avast.
Please see this article on how to generate a screenshot. https://support.avast.com/en-ww/article/Create-screenshot
(when replying click on + Attachments and other options to add the screenshot to your post)