Problems with email delivery rates through SendGrid

We're havi开发者_开发知识库ng problems with email delivery on our web app. It seems to be very irregular, in the sense that most of the time we have a 95% activation rate once a user has created an account - but on the odd day (like today) we have only a 40% activation rate.

We talked to SendGrid and they said their system is reporting the email sent, and to have user check the spam boxes - but the users claim their are no emails in the spam boxes.

Does anyone have any idea what might be going on? It's beginning to be a problem as we get multiple support tickets daily from users who can't activate.

One influencing factor might be that most of our users use .edu email addresses.

Thanks!

Walker

It's probably happening on the receiving end.

When we had this problem (only with confirmation emails) we decided to add an Unsubscribe link (even though it doesn't make sense) and our delivarability went way up.

This happens because most mail servers look for an unsub link, and treat emails without one as instant spam, not letting it get to the user.

I had a similar issue and my problem ended up being that I had a bounce at one time so the email never sent to that address again. If it is a bounce issue, you can clean out the bounce log in your sendgrid account and it should at least try to send the email again.

This seems to be the mail relay server bouncing the mails, because sendgrid is not using static mail server IPs. I am having the same problem and I am getting bounces with messages like the following:

554 IP ip identified as dialup. We dont accept mails from your mailserver, because the server is using a dymamic IP number. Mailserver should use a static IP. Please contact abuse@ispgateway.de if this is an error. In case of doubt please contact your systemadministrator or provider.

Check your whitelist wizard for an additional SMTP server to configure in DNS... it looks like that may well be our issue.