Unable to send email all day

[#1]

Get's to 93% delivered - then see attachment for error message. Happens every time. Messages are not spam, and my machine is virus free - use MS defender (Windows 10) and MalwareBytes Premium. Please fix. I need to be able to send emails from my desktop. 

[#2]

Hi @JeremyP99

Sorry to hear you are having this issue.

Can I ask what Mail Client you are using which is spitting out this error code?

Could you please trying logging into your webmail and attempt to send the email via that platform please?

Let us know how you get on.

Thanks

Alisdair

[#3]

Thunderbird. Been using it for years. I use pop3 not imap, for security reasons, so have no webmail account set up, and the Plusnet account is in my wife's name, so it would be her mail I got not mine, I suspect?

[#4]

POP3 and IMAP offer no differing security considerations, they are simply different ways of READING your email.  They BOTH send email via the same SMTP service.

If you do not see your wife's email now, you will not see it if you access YOUR email address via webmail.

To log on to  a specific mailbox using webmail, use accountname+mailboxname as the user name (mailboxname@accountname.plus.com should also work).

Are you encountering this issue out of SENDING and NEW email or when REPLYING to a RECIEVED email?

Are there any URLs in the email content?  They are the usual cause of suspected spam rejections.

[#5]

I was forwarding a mail to me to my wife. It's a weekly email which I always forward and have had no problem doing so before. Probably URLs in it, but one does need to be able to email URLs. Also, I'm aware of the differences between pop3 and imap, and use pop3 so that my emails are held locally and not on the web. As noted, for security. I do not use webmail. 

Was able to sent a test message with one word in it and to forward a longer message, so it may be something to do with the email itself. I'll keep an eye on it - meanwhile, feel free to close this as I can't see us progressing it. 

Thanks!

[#6]

URLs can become suspect if they are seen to be associated with spam activity or virus distribution.  This can arise from a multitude of people incorrectly reporting emails as spam, with the consequence that spam filtering services "learn" incorrect profiles.  It is not the issue of forwarding URLs generically which is the issue here, but rather specific URLs believed to present a risk.

It would be worth attempting to send an email containing only the URLs (one at a time) found in the email, until the offending one is identified.  Plusnet staff can then arrange for the blocking to be reviewed.  Previously attempting to send an email with just badurl.com in the title is enough to trigger rejection.

As for security, using POP3 in preference to IMAP to automatically download emails as a back up, is one thing, but not a security matter as normally understood by the term.

In the context of security, what do you considered to be "unsecure" about webmail access?  Arguably given the options available, it is the most secure means of accessing your Plusnet email, as it is encrypted (https) end to end, whereas neither POP3 nor IMAP are.