> of course you will be able to, but your e-mails won't reach most customers
Unfortunately, I found this to already be somewhat of a reality. Even with all the best practices I went to, many MTAs simply don't trust my IP address. Most "sane" MTAs seem to greylist me rather than blacklist outright, so it just adds a bit of delay to users receiving their emails. Thankfully it seems to be gradually getting better, but gone are the days of simply pointing your apps at sendmail letting them go.
Unfortunately, I found this to already be somewhat of a reality. Even with all the best practices I went to, many MTAs simply don't trust my IP address. Most "sane" MTAs seem to greylist me rather than blacklist outright, so it just adds a bit of delay to users receiving their emails. Thankfully it seems to be gradually getting better, but gone are the days of simply pointing your apps at sendmail letting them go.