We built web applications which create a fair amount of transactional emails, such as tickets, reminders and logging messages. These emails are typically sent to end users, but most of them are also sent to users inside the client organisation, directly or via Bcc.
Our solutions are typically hosted on a web server separate from the email server and outside of the clients network.
We are finding that we have a lot of problems with email delivery to client internal staff, ie. The Bcc messages are not delivered due to spam filtering. Many of the email servers are Exchange with external add-on packages like Trendmicro, Symantec and GFI-Maxmail. Often we don't have control over the settings of the spam filters or getting around the spam filter requires to send from a specific email account - where we would rather send from the internal staff member.
I've followed Amazon SES and it appears to be a viable alternative, the cost of sending the emails certainly outweighs the effort of getting through spam filters and support requests.
Has something like Amazon SES improved anyone here on Serverfault's chances getting through spam filters? A subjective answer is fine.
You can assume that emails have non-critical content, have valid sender addresses and that SPF is setup correctly.
Amazon SES states the following in their FAQ:
You also have some other alternatives to SES that, while they cost more, may give you other features that you are looking for and may need. Here's a list of other transactional email providers:
All of them have free accounts that you can kick the tires with and see which has the best deliverability for the specific types of recipient SMTP servers that are acceptable for you.
{FULL DISCLOSURE: I am the Product Manager of PostageApp. Let me know if you have any questions about any of this!)