I'm running an app at www.universitytutor.com which lets people find tutors. Most of the tutors are college students.
We send out a follow up email 2 weeks after someone contacts a tutor to ask how it went and currently 70% of them say the tutor never responded to their inquiry!
So I'm trying to figure out how we can improve the deliverability of emails to our tutors. We're running postfix on ubuntu. Here is all the stuff I've checked:
- The server IP (220.127.116.11) is not on any blacklists
- RDNS is configured correctly and resolves to a FQDN
- we have SPF records in place
- using DKIM signatures on outgoing emails
The volume is still pretty low (maybe 500 messages per day). And most of them are unique where one person contacted another with a specific inquiry, so it's not bulk mail. I've spot checked the messages going through the site (for tutoring jobs) and they are legitimate, warranting a response and a possible job for the tutor. I can't see any reason why they wouldn't respond if they had actually gotten the email.
All the tutors had to click a confirmation link in an email when they created their account so I KNOW they got at least one email from us. We also automatically take down tutor profiles when someone reports they didn't respond. So I don't think it's a situation that built up over time where most of the tutors have graduated and are now gone. 70% is too high to be explained just by that.
I've wondered if it could be something special with university email servers? Most of the tutors are college students and have .edu email addresses. Is there anything special to worry about here in terms of deliverability to .edu mail servers?
Or am I missing something else with my mail server configuration that is causing these messages to get lost in spam filters?
Let me know if there is any other info I can provide which might be helpful.
P.S. When sending test messages to myself from the site they always come through (Gmail shows a 'pass' in the headers for both SPF and DKIM). I've tested it with Gmail and Yahoo which both work but obviously I can't get an account on their .edu mail servers to see if it works there.