[massaman_yams]

Right. Split up by IP/subdomain if possible, preferably within one provider.

That said, you may be surprised by the number of large organizations that have a dozen or more services that send mail on their behalf, for various different purposes... it's not optimal, from a deliverability perspective, but it's also not usually going to cause deliverability issues by itself as long as everything else is in order.

[webbie917]

Yes, agreed. Lotsa factors in play when it comes to deliverability, like a puzzle. What a well established brand (with high quality emails) can get away with isn't something that businesses with less resources should try to copy though IMO.

Just saw an email from Starbucks in the spam folder - all because of a few words that no doubt triggered the spam filter.