Magic Netgear Router – Emailing without a valid password?

[#1]

Hi Folks
This one has me puzzled. I had a router (not mine) set up to email my plusnet account with the router log once a week. The router was about change ownership so I got access to it and thought I removed the emailing details from it.
Somehow I must have made a mistake because the router continued emailing me once a week, after a few weeks, as I couldn’t get access to the router to try again I decided that I was probably overdue to change my plusnet password so I dutifully did this confident that the router would now fail to log in to the plusnet mail server to email me the weekly log.
Bizarrely the log keeps arriving, when I set it up the router asked for the outgoing mail server (relay.plus.net) how is this router sending these emails without a valid password? The router is /was attached to a btconnect account, there are no btconnect email server details held on the router so am I right in saying that the emails cannot be arriving via btconnect?
Which bit of the blindingly obvious am I missing?

[#2]

Perhaps I am missing the obvious here, but surely if the router is sending you an email it doesn't need a password for your email account, in the same way that nobody else who sends you an email needs to know your account password. Presumably the router is using the account of whoever owns it now. Unless you know the new owner I suggest you just add it to your blacklist.

[#3]

Hi Denzil
That is what I thought at first and I guess it must be the case, but if so it seems strange that the router requires you to enter an ougoing mail server address.
Cheers

[#4]

The Router help screen seems to suggest it is logging in to plusnet, see attached.

[#5]

Presumably you have left the "My Mail Server requires authentication" blank (you should have done), in which case the username and password are ignored. As it is still sending you must have omitted to remove your email address from Send To This E-mail Address.

[#6]

To send e-mail (through a Plusnet connection) the router does not need to use a password.
But to send e-mails using relay.plus.net (Plusnet's SMTP server) using another ISP then a password is required.
I can think of three ways that its working;
1) BT are redirecting connections to relay.plus.net to their own SMTP server.
2) relay.plus.net is allowing unauthenticated connections from BT connect, perhapps due t the RIN trial, where Plusnet customers are using BT's network.
3) The authentication details used for ASMTP are the main account details, and you changed a mailbox password.
If you can post up the e-mail message headers we should be able to see if the mail is coming via Plusnet or BT mail servers.

[#7]

RIN is the answer.
Because Plusnet PAYG RIN users connect on the BTConnect IP address ranges, Plusnet have had to allow those ranges on relay.plus.net. That's why it's still working.
Edit: Just remembered, when the RIN trial started there were problems with people on particular IP ranges being unable to send emails because some ranges were missing.

[#8]

Cheers chaps, there had to be a logical answer