With online email service invite systems that many web apps use these days, do you send the invites through the user's account within that service or is it more proper to harvest the contact addresses and send from the new (your) web apps email domain?<p>If the latter how do you avoid spam filters?
Translation: Should an invite from your service (for ex, Evite) be sent from @evite.com or @gmail.com if your friend betty@gmail.com is sending someone an Evite.
I would suggest sending the emails from your own app/domain. Make sure your reverse dns is setup correctly.<p>Check out www.isipp.com for email whitelisting services.<p>Try lyris or ecelerity software for sending out emails. It costs about $1,000 for a license but it is worth the money for the bounce handling, error reporting, setting different time-between sending messages to particular hosts, etc.
I recently struggled with this and ultimately I went with using address from our own domain. There were a variety of reasons but it came down to:<p>1 - Trust for the sender and recipient (we weren't masquerading as someone else, like NikePlus does)<p>2 - Trust for mail servers (so they're not receiving Gmail branded email from a non-Gmail server)<p>3 - Allowed integration with companies such as Exact Target who offer "deliverability" as a product (<a href="http://email.exacttarget.com/Services/Deliverability.html" rel="nofollow">http://email.exacttarget.com/Services/Deliverability.html</a>). This requires it to come from our domain<p>Facebook's approach seems like good etiquette; I've certainly never heard anyone complain about it...so I'm using a similar approach.
Does any service actually let you send emails through a user's account via some sort of API? If you're just using their username and password to log into the service and send the email as them, that strikes me as considerably sketchy. Don't do it. Send the invite from your domain.<p>I don't know how to avoid spam filters other than what Googling for it gives me. It'd be interesting to hear what has worked from people who have actually had to do it.