The ability to send emails from any place in all over world, using different servers as well! I can't think of anything negative about this service atm since it is very easy for me use their services because they are affordable compared with other companies that charge you hundreds or thousands per month just so your email will go through them (which never happens).
They have great customer support who's always willing help out when needed even if its late into night/early morning time zone difference which makes things easier than ever before!! This has been my only mail provider until now due mostly do cost reasons but also ease-of -use factor too much people around here don’t know what an SMTPMailer class object really does nor how important one would be considering most business owners aren;'ts familiar enough woth such tools yet either way we need our own domain address hence why i chose OBM instead.