Unable to send email from Doro 5516

[Maddy]

I recently got a new Doro 5516 but am unable to send emails from my Plusnet account.  I can receive them with no problems but as soon as I try to send one a message pops up instantly saying 'sending' and then another which says 'failed'.  I have played around with various settings such as port numbers etc:  I contacted Doro and was told to raise the issue with the network provider, however the advisor in the local o2 shop wasn't helpful - in fact he didn't even know how to switch the phone on.  I returned the phone to Mobile Phones Direct who replaced it without any qualms, however, none of the above has resolved the issue.  I notice from the community pages that quite a few people have this problem.

I would be eternally grateful if anyone could tell me what settings I should be using together with any other useful hints.

Many thanks.

[MI5]

@Maddy 

Try these in your outgoing (smtp) settings.

[MI5]

Your email username and password
Setting up for the first time
Email username: Your Account username
Email password: Your Account password
Your Account username and password are the ones you log in to the plusnet website with.

[Maddy]

I'm sorry I don't understand your last message.  What are you asking me to do.

[MI5]

@Maddy 

You need to open the email settings on your phone, go to the outgoing mail settings and enter the details as posted above.

[Maddy]

Thank you for your reply unfortunately I still cannot send email.  My Settings are as follows;

Server

[Maddy]

Thank you for your reply, unfortunately I still cannot send emails.  My settings are as follows;

Server      relay.plus.net

Port         587

Security   SSL/TLS

Authentication OFF

[MI5]

@Maddy 

Change security to <none>

[Maddy]

Changed security to off - send failed again

[MI5]

@Maddy 

Authentication on and enter your username and password.