Outlook Mail, Suddenly Won’t Send Mail with Usual Plusnet Settings.

[#1]

Mail with UsualSuddenly this morning, I have found I cannot send emails in my Outlook mail.  I can receive them.  When I check in Advanced Settings, it connects to the incoming Mail Server IMAP, but can't connect to the outgoing Mail Server SMTP & says to contact your Internet Provider if this continues, which it is doing.  Can you help?

[#2]

There are numerous reasons why this could happen and none of them have anything to do with your IMAP settings or your password.

Is Plusnet your ISP? In other words, is this a legacy email account?

Are you using a VPN?

Are you connecting over 3/4/5G mobile services?

[#3]

Thank you for your reply.  Yes, Plusnet is my ISP.  No, not using VPN.  Connecting with desktop PC as usually do, not with a mobile service. The email just sits in my Outbox.  Tried the work Offline method but that doesn't help.

[#4]

Moderators Note

Title changed from all upper case as per Forum rules

[#5]

So, the usual guess work is not going to help...

• You are using a PC (no mobile network involved)
• Connected to a current Plusnet account / mailbox (not accessing a legacy email account via a third-party ISP)
• You are not using a VPN (not accessing the SMTP server from an apparently third-party IP address - possibly overseas)
• You can receive email, but not send it (that infers that the username / password is not the issue)

When you try to send an email, exactly what happens?  What error message (code) do you get?

You refer to "Outlook" but are not clear which of the many products which masquerade as "Outlook".

Can you send emails if you log into the mailbox using https://webmail.plus.net (verification of success / fail here would eliminate an account configuration issue).  Being able to successfully send emails via webmail leads to considering an obscure network issue.

Email applications are not overly helpful in being clear why they cannot access SMTP servers - they will generally report "password error" for all failure events.  In situations such as this, running manual diagnostics can be helpful...

Test SMTP authentication

Email programs often report username / password error for issues not actually related to those being wrong, but for other connectivity issues. Such can be very frustrating when you are convinced that they are correct. Testing SMTP authentication through a command line interface can deliver a more precise error message. The following describes how to do this using TELNET.

This is not difficult, but you need the following resources which might be unfamiliar...

1. TELNET - this might need installing as an additional option, for Windows see enabling TELNET.
2. A code64 encoder / decoder such as this.

You can use TELNET to communicate direct with the SMTP server as follows...

Open the code64 encoder in a web browser and leave ready for use in the following steps.

Launch a windows command line window (DOS window) - press windows-key+R - type CMD into the run box - click OK

Enter...

telnet relay.plus.net 587

Press enter. Note if you use one of the other brand email services, use the appropriate SMTP server name for that brand. In response to SMTP server I'm here message, say 'HELLO'...

EHLO relay.plus.net

The SMTP server will then report what it can do after which tell the server you wish to authenticate...

AUTH login

The server should return the following, which is a base64 encoded string that requires your username:

334 VXNlcm5hbWU6

Use the code64 encoder to encode your username and paste it into the telnet window and press enter. For example:

bXl1c2VybmFtZQ==

The server should return the following, which is a base64 encoded string that requires your password:

334 UGFzc3dvcmQ6

Paste the base64 encoded password for the username. For example:

bXlwYXNzd29yZA==

The server will then report success or failure, any failure message should clearly indicate the reason for the failure. If the reason for the failure is not clear, please report back the message.

Close the SMTP / TELNET session by entering

quit

The session should look something similar to the below wherein your input is in bold...

220 avasout03 smtp relay.plus.net
EHLO relay.plus.net
250-avasout03 hello [your IP address], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 104857600
250-PIPELINING
250-8BITMIME
250-STARTTLS
250 OK
AUTH LOGIN
334 VXNlcm5hbWU6
bXl1c2VybmFtZQ==
334 UGFzc3dvcmQ6
bXlwYXNzd29yZA==
235 ... authentication succeeded
quit
221 avasout03 smtp closing connection
Connection to host lost.

Here are some examples of failure responses...

535 ...authentication rejected [as username / password is wrong]
535 ...authentication rejected as source IP has a poor reputation
535 Too many SMTP auth failures. Please try again later.

[#6]

Hi there~

I don't get an error message, the mail just sits in my Outbox.

If I do go to Account Settings, Advanced - it says Searching for my settings for my email address, which is correct. Having trouble connecting to my account, though I am connected to the Internet. It can log onto the incoming mail server IMAP port 143.  Re: test email, can't connect to the outgoing SMTP server port 25.  Tried other outgoing ports but no effect.

[#7]

Meant to say my Outlook email programme is part of my Microsoft Office 2013 along with Word, Publisher, Excel, Access, PowerPoint etc. Never had a problem with Outlook before.

[#8]

Sounds as though you are allowing Outlook to self configure with unencrypted connections. You MUST configure the server settings manually.

[#9]

I did set them up manually originally.

Perhaps I need to reset my account again.

[#10]

PS  Plusnet Webmail works to send mail.

[#11]

That is helpful - there is no issue with the account, username or password. You thus need to focus on the server settings in your email application.

You might try stopping and restarting Outlook or starting it in safe mode. I have seen connection issues self heal after doing the above!

[#12]

Unfortunately that didn't work.  I notice when the email sits in the Outbox, the programme is continually trying to send it, which stops other operations.  The email in the Outbox is difficult to delete & have to move it to Trash where it goes eventually.

[#13]

Still doesn't work - nothing was changed this end - Outlook just decided it couldn't connect with the outgoing server but could with the incoming one!!!  So made a new account with gmail.com!!!

Thank you for your help.

[#14 · Accepted solution]

Solved - Outgoing Server needed authentication ticked - same as Incoming server!