Simon Ward said:
Since you made this change, thunderbird thinks this of emails: "This message may be a scam"
This shouldn't have made any difference, as I only had the .htaccess rewrite rule in place for 2 minutes, and then moved it back.
Our site e-mail is handled by Mandrillapp.com and we have valid DKIM and SPF entried
v=spf1 +a +mx +ip4:89.145.112.71 +ip4:89.145.112.72 +include:spf.mandrillapp.com +include:hotmail.com ?all
k=rsa;p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCrLHiExVd55zd/IQ/J/mRwSRMAocV/hMB3jXwaHH36d9NaVynQFYV8NaWi69c1veUtRzGt7yAioXqLj7Z4TeEUoOLgrKsn8YnckGs9i3B3tVFB+Ch/4mPhXWiNfNdynHWBcPcbJ8kjEQ2U8y78dHZj1YeRXXVvWob2OaKynO8/lQIDAQAB;
Do you know roughly the time the first e-mail was flagged as a scan?