Is anyone else experiencing this? Tonight I've tried to e-mail from my Plusnet account to 2 separate Yahoo addresses, and received NDNs like:
SMTP error from remote mailer after initial connection:
host mx5.mail.yahoo.com [22.214.171.124]: 553 Mail from 126.96.36.199 not allowed - VS99-IP1 deferred - see help.yahoo.com/help/us/mail/defer/defer-02.html (#5.7.1)
[188.8.131.52 is ptb-mailc04.plus.net]
Is PlusNet running an open relay?? I've had no problems mailing to Yahoo before tonight...