Somewhat OT: Mail Relay Services

[Tim Daneliuk]

For many years, I've run a mail system built on FreeBSD for my own small business.
It's been as flawless as any mail server ever can be, requiring only periodic
maintenance and updates.

The primary server runs in a 3rd party cloud environment.  We are starting to
see parts of their network blacklisted by the various UCE blackholing services.
Unfortunately, they don't just blackhole a single IP, but an entire subnet at
a time, which catches us in the mix.

The big mail hubs like outlook.com no longer have a mechanism for removing the block
for a single ip and kick you back to your ISP or hosting provider for resolution.

So ... we are contemplating using a smart host to do all our outbound email for us
via relays from our own mail servers.  Presumably, such a smart host would be better
equipped to deal with bad blacklisting and delivery issues.

So ... does anyone have experience or recommendations as to who would be a good
provider for a low volume, small business mail relay?