Got an email recently from Google saying that email that I had sent was not being delivered because it was spam.
The exact message was:
“The response from the remote server was: 558 5.7.1 635B039B043B5F93 Message content rejected due to suspected spam. IB703”
This is the first time I think I have ever got a notification indicating that email, that I had sent, was spam.
The email was about a fourth message in a series that I had sent to some of my cousins. 9 recipients.
The first email was inviting my cousins to a Zoom meeting, seeing I had not seen some of them for many years. The second was the setting up of the meeting. The third was a reminder that the meeting was going to take place and the fourth was to inform them that a recording of the meeting was available,with a link to the recording.
All 4 messages went to the same people but for only the last one had the bounce back because of the suspect spam and then only for 3 of the recipients. All those receipens had a bigpond email address.
The 3 bounce backs took about 4 hours to get to my inbox
As the recording of the meeting, that I had uploaded to Google Drive, for some unknown reason, would not play, I uploaded it a second time and sent a subsequent email notifying of the updated link to the video. I got no bounce backs from that email.
I new the video was not playing because I tried playing it myself and got a message saying that the file was still being processed, and to return back later. On subsequent trying to play the video, I still got the same message.
Considering all the above, it would seem that the BigPond spam checker, checks the contents of a linked video, and if it cant be played, considers the email to be spam.
Other than the possibility that the BigPond mail servers are very slow, that may be the reason it took 4 hours to tell me, my email was suspected spam.
If bigpond are checking links to videos, for spam in the videos, then that would take a lot of computing resources. Some videos can be multiple GBs.
On googling the code of the spam rejection I found this. A system administrator criticising BigPond for ther attitude towards spam. But nothing about checking linked videos for spam.
Some things I found out about email security:
Definition. The Sender Policy Framework (SPF) is an email authentication protocol and part of email cybersecurity used to stop phishing attacks. It allows your company to specify who is allowed to send email on behalf of your domain.
DKIM (DomainKeys Identified Mail) is a protocol that allows an organisation to take responsibility for transmitting a message by signing it in a way that mailbox providers can verify. DKIM record verification is made possible through cryptographic authentication.