I'm working on a app which sends notifications emails. I know this is stereotypical for spam servers. I know the first question ist "How can I ensure what my server will not be listed as a spam server?" However I believe I should monitor my mailserver to ensure what every customer becomes his mails.
So the question: How can I check/monitor whether my server is listed as a spam server?
I really appreciate your help.
MXtoolbox (disclosure: I hold no relation to this site) has a great blacklist checking tool that checks all the major blacklists.
As for staying off them, make sure all your e-mails are opt-in and have an unsubscribe link within the e-mail body of every notification sent. Keep a record of all clients opting in, some hosting companies will charge you a small fortune if you get their IPs blacklisted.