Hello Popowich, Tutanota team here. We would like to look into the issue. Could you tell us which tool you used to get this graph? Thank you very much!
The graph is from the Sender Score site. Sender Score's are a report card for your outgoing email reputation.
The sender score reputation for an IP address is used by many email services to help determine what to do with an incoming email connection, and the actual email if the transaction gets that far.
Many providers will reject connections from IP address with low sender scores. I typically see rejects increase significantly when a score drops below 60.
At 73 I'd expect some services to be blocking and some to be delivering to the spam folder. It's one of many potential checks in an email services anti-spam toolbox.
@Tutanota How is it going? I'm curious what other technical issues may be going on. I see that you added sending limits. Was the source of the problem free accounts being used to spam and no other troubles?
@popowich Yes, the score (now at 61) is constantly getting better as our measures take effect. The main change was that the number of emails per free account per day are now limited so that Tutanota is probably not attractive to spammers anymore. In addition we block email addresses if someone forwards a spam email to us.