SQL Server Replication Snapshot Agent login fails
I have used a Domain Account for Snapshot Agent and Log Reader Agent,
  called SQLAgent.


If you check this answer:

The process could not connect to Subscriber 

you will see that the SQLAgent account must have a login on your ServerB and must be a db_owner on your subscription database there.

It does not need to be a sysadmin on your ServerA.

It has though, to have sufficient permissions on your snapshot folder wherever you decide that should be.