Having problems sending faxes via www.tpc.int. It reports that there is no message ID on my emails, so rejects them. No problems if I send emails using my work system, or using mail2web (which puts its own message ID) with my Plus account.
I raised this as problem with support (ticket #14663789) last week, but have been assured that Plus does add correct headers to emails.
So, using webmail and Outlook from work is OK with TPC. Using Mail2web is OK with TPC, but using Outlook via smtp with Plus is not OK and using the (ssslllooowww) webmail is not OK (so it isn't a client issue).
I also found the post on the Beta section of these forums, post number 17929, raising the same issue in June.