[superasn]

I think your best bet is Amazon ses. In my recent testing, all mail always go through - unless the recipient marks it thus.

It's damn cheap too, like almost free for low volumes.

I think Amazon uses this for their workmail also and has become pretty strict at policing abuse.

I am only speaking for gmail though, so ymmv for hotmail et al which I haven't checked.

[sirnoggin]

Interesting just met a client who us using Amazon SES with a few domains, all of his emails go to spam, across all domains. Curious aye! Almost like these sender's aren't inpregnable and there is something else going on.

[quickthrower2]

I agree. Amazingly cheap. Worth a little bit more technical hassle (looking at templating and batching for example IIRC you had to do for marketing or bulk transactional emails) but still amazing value for money.