The essential explanation behind mail not being sent is if it is being classed as spam.If an email has been assigned as spam, it might be received by one email address yet then not forwarded-on to the following email address. This helps the reputation of the server and prevents blacklisting.
To determine this, you can take a try at bringing down the spam channel by means of Junk Filters inside the HamroCP control panel.
To do this:
1. Login to Hamro.Cloud
2. Find the package containing the forwarder and select Junk Filters
3. You could likewise take a try at whitelisting the domain/email address, the email is originating from.
