When I create a droplet with Digital Ocean or Vultr to install Mail-in-a-Box, do I need to submit a ticket to the hosting provider to ask them open any port for the mail server to work?
Because I am using the email to register on social network sites like Wordpress, and Tumblr, they will send me their verification emails, and If I want to accept all incoming emails without spam filters, how do I configure it?
The answer depends … traditionally DO has always had the mail ports opened for use. But due to abuse they have recently changed their policies. Now it seems that new clients (accounts opened less than 30 days) have to request mail ports to be unblocked.
I, as a rule, always submit a ticket to a new (to me) provider and ask them if they block mail ports, and if so what the procedure is to unblock them.
The spam filters will not block emails from these sources. These emails are not spam and are not treated as spam. So no worries there.
However … Mail-in-a-Box uses greylisting which means that the first email from a specific mailer will be delayed, so expect that these mails will, in many but not all cases, be delayed.