I have a client who communicates with me via email. Crazy, I know.
Here is the issue: When I send him an email from Mac Mail — with my URL in the footer – he receives it. However, when he tries to reply from his gmail account, my server bounces it back to him. The error is "554 rejected due to spam content". (a false-positive)
I can not collect the Spam Checker data from his email headers, as he is not tech savvy. I can not duplicate the error using a gmail account of my own. I have eliminated all possible problems, except the URL in my footer, which triggers this every time.
My email server is: 01-ah-r28u33-ss05.alphahosting.com
His gmail server is: mail-ob0-f172.google.com
Both of these (and also my test gmail server) are shared servers and have some blacklist reports. However, I have no such problems from other clients. My concern is that this could be a reporting problem, and I am failing to hear from those who would rather delete my email than give me a call. I think that you can understand my concern.
Please help, and do let me know if you need any other data that I might add in here.