Found this the other week when someone alerted me that emails from my custom domain were showing as possible spam in Gmail - it worked perfectly to help me fix

Found this the other week when someone alerted me that emails from my custom domain were showing as possible spam in Gmail - it worked perfectly to help me fix the problem (duplicate SPF records). It's frustrating that all my mail could have been triggering spam alerts for months without me knowing. I'm lucky someone kind reached out to tell me. It would be great to have a service automatically alert you if your messages look "spammy" (although I know real spammers would probably abuse it).