Unable to send email

[#1]

No issue until today.  I have been able to send and receive emails up to about 9am today.  I am using Outlook 365 and the email goes into the Out folder and stays there. 

Every now and then a message showing the correct relay server (relay.plus.net) pops up asking me to confirm the username and password which I then confirm.  The message keeps popping up every time II have not changed anything.  No issue receiving emails. 

When trying tos end test message in Outlook account settings reads "Send test email message: The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP)." 

Any advice as not sure where the issue may be?  Thanks.

[#2]

There are a host of reasons for this symptom, none of which are related to the password ... but most email clients do not discern the real cause - they just ask for the password.  You have not provided any details of the context of this issue...

• Are you connecting over a Plusnet connection - that is not mobile or VPN
• Are you a current customer or is this a legacy email account
• Which email brand is this

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.

[#3]

I was using my mobile phone as a Hotspot and I have had no issues in the past.  I am a current customer and have been for several years.  My email client is Outlook 365.

Sorry I am not that computer literate and although I got as far as enabling the Telnet thing that was as much as I understood.  the rest is goobly [-Censored-] to me.

[#4]

Just follow the instructions step by step or do some research.

The fact that you are trying to connect over a mobile network is probably the source of your issue.  The mobile probably has acquired an IP address with a bad reputation and thus for the protection of all users, the connection is being blocked.

Try getting the Outlook working over the Plusnet connection with authentication set.  If it then does not work via other connection methods, the issue is the other connection.

[#5]

We are back home again and it still did n to work.  After several attempts for some reason it sprung back to life after I deleted the old POP3 account and set another account up using the same details.

We go away in our caravan often and do not recall having this issue previously even when touring the continent although that was last about 6 years ago.  How can i prevent this happening in future?  Thanks.

[#6]

If the mobile IP address you pick up has a bad reputation there is nothing you can do about it, beyond turning off mobile data / access for a while, then see if you get a different IP address when turning it back on.

[#7]

Thanks for the advice and help.  We are with Three and have been for probably 20 years.  No issue using hotspot Thursday, Friday and then Saturday morning it stopped after download mail that day.