As per our earlier blog post about Magnet’s Simply Broadband – we forgot to mention that Magnet blocks TCP Port 25 outbound on it’s residential accounts.

Their solution is to change the SMTP server to theirs: smtp.magnet.ie

In some cases, this is not suitable.  You can try changing the outgoing port to 26 – some hosting companies, such as Spiralhosting, offer this facility.

The other solution is to use SSL SMTP – port 465.