E-mail and Avast..... WTF

You software for no apparent rhyme or reason, on occasion without any warning stop (not allow) throughput of my e-mail. Been going on for a long time. How does something like this continue without resolution???

How does something like this continue without resolution???
If no one report a problem, they cant fix it

Is it a receiving or sending problem?

Does the problem go away if you turn off mail shield?

What mail client do you use?