I sent an email yesterday that got sent back as undeliverable with the following error message:
552 MCMiqjhnUqd5lMCMkq2caw message rejected due to spam or virus.
reading some threads on this forum I noticed that this generally happens when your message contains a URL that is listed on your spam list.
my email had contained two attachments, one of which was a plain text file and this had five URL's in it. after testing them I narrowed it down to this one: https://www.thecourier.co.uk/fp/past-times/2050510/cobbled-streets-a-riot-of-colour-as-dundee-hosted...
this is on the website of a newspaper, the Dundee Courier, and I suspect that does not need to be on your spam list. I got my email to go by inserting spaces to break the URL down into chunks so that your primitive software can't recognise it as a URL. that works, and I thought other folk might like to know.
take care
Kaarlo
