Outgoing mail from iphone

[#1]

Hi,

I've tried googling my question but none of the fixes have worked so would like some help please.  Because of the ongoing problems with webmail I'm setting up to receive emails via my iPhone. I can receive email fine but cannot send I just get error messages saying their email has been rejected by the server.  My incoming mail is on imap.plus.net and works fine, my outgoing mail server is relay.plus.net. I've tried leaving username and password blank, but also tried with my username and password (though it comes up with error message saying they are incorrect when I know it is definitely right). I've also tried with and without usernames on port 587 and port 25 still with no luck. I'm on Vodafone but I'm not sure if its an error for Vodafone phone users or whats causing the error.  Any help would be much appreciated

[#2]

First things first, you didn't mention are you connecting via wifi or mobile internet?

[#3]

I didn't think of that but have just checked with username and without username, on port 587 and on port 25 both with wifi and mobile internet and none of the options are successful at sending emails.

[#4]

works fine for me on voda port 587

[#5]

@Jononeill

Are you by any chance still waiting for your Plusnet broadband service to activate? I.E is your WiFi connection with a different ISP? Until users have an active Plusnet broadband account authentication is not permitted.