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relay.plus.net not working?

TieKnot
Dabbler
Posts: 13
Thanks: 6
Registered: ‎06-01-2014

relay.plus.net not working?

Hi,

Is there a problem with relay.plus.net?  I currently can't send emails on my Plusnet hosted account - can receive OK on imap.  Outlook affected on both tablet and laptop, and Gmail app on mobile phone.  Any suggestions as to what I can do?  If it's a Plusnet issue how do I escalate?  Affects ports 587 and 25. 

Currently stumped.

Please advise,

TieKnot

 Outlook currently can't login.Outlook currently can't login.

 

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12 REPLIES 12
jab1
Aspiring Legend
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Registered: ‎24-02-2012

Re: relay.plus.net not working?

@TieKnot Just sent a test message with no problem. What email client(s) are you using, and what, if any, error messages are you seeing, other than the request for name/password as in your post?

John
MisterW
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Re: relay.plus.net not working?

@TieKnot are you trying to send from a non-PlusNet connection e.g mobile or public wifi ?

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.

TieKnot
Dabbler
Posts: 13
Thanks: 6
Registered: ‎06-01-2014

Re: relay.plus.net not working?

On my W10 tablet I'm using Microsoft(Office) 365 Outlook client

 Capture.JPG

On the laptop, it's build 13231.20262 (same version)

And the it's latest Gmail for android on my mobile - where the message is sitting as unsent.

I've been using the settings for ages ... and I don't know what's caused the issue.  No other error message that I can see as yet

TieKnot
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Registered: ‎06-01-2014

Re: relay.plus.net not working?

@MisterW - Since moving in with my partner, I access internet via Sky.com (:-().  My mobile is with O2.

MisterW
Superuser
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Registered: ‎30-07-2007

Re: relay.plus.net not working?

@TieKnot thanks. My GUESS is that your IP has been blacklisted. Even though you are using authentication, the Cloudmark antispam system uses an IP reputation system and will refuse connection if your IP reputation is poor. The smtp server (relay.plus.net ) will return a different error in this case but I'm afraid that most email clients don't handle it very well and just return a generic 'login failure' back to the user. Any blacklisting along these lines is usually temporary.

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.

Townman
Superuser
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Registered: ‎22-08-2007

Re: relay.plus.net not working?

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

 

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.

TieKnot
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Registered: ‎06-01-2014

Re: relay.plus.net not working?

I'll check this out later.  Thx.

TieKnot
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Posts: 13
Thanks: 6
Registered: ‎06-01-2014

Re: relay.plus.net not working?

Hi @MisterW and @Townman,  my emails started to be sent about 60-90 mins ago.  I hadn't done anything.  Nevertheless I did persevere with @Townman debug process and the outcome was authentication succeeded - which wasn't to be unexpected if  emails were now being sent from the Outlook client (on Windows with Sky as carrier) and the Gmail client (on Android with O2 as carrier.  I don't know if this supports @MisterW's suspicions.

It would be great to know if anything was knowingly done at the Plusnet end or whether some sort of whitelisting had done it - and which entity could have been whitelisted.  As two 'independent' routes (my laptop and my phone) to relay.plus.net seem to have unblocked at the same time, my finger of suspicion points to relay.plus.net.

If you can help me understand what might have happened, that would be great.  Thanks in anticipation.   Next time I'll try to use @Townman's procedure sooner.  It's just that I had work to do. 😞

Townman
Superuser
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Re: relay.plus.net not working?

There are two potential scenarios.

1. You had a blackballed IP address, your router (for whatever reason) dropped (at least) the PPP session with your ISP and then acquired a different (clean) IP address.

2. The blackballing on the IP address has been listed. I’ve seen a blocked IP address after 24-48 hours.

Without you having knowledge of the IP address(es) when failing / working and confirmation of the authentication failure reason, all that we can do is presume a probable cause based on past experience.

You can be assured that nothing of substance will have occurred at the PlusNET end ... beyond the “policing” system revising the blackballed IP status.

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.

MisterW
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Re: relay.plus.net not working?

and the Gmail client (on Android with O2 as carrier

was your phone actually using the mobile network or could it have been connected to your home WiFi at the time of failure to send ?

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.

TieKnot
Dabbler
Posts: 13
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Registered: ‎06-01-2014

Re: relay.plus.net not working?

Fair point! I think it would have been using domestic WiFi. And I'm never out and about these days ;-). So it would have journeyed via the router and Sky before hitting O2 and/or Plusnet. Thanks for spotting this part of my description as I guess that tends to support something being blacklisted or some other connectivity issue somewhere on the journey to relay.plus.net.

If it happens again, I'll try to do those telnet diagnostics sooner.

(Separately we are having issues with Sky as we are randomly and intermittently losing service for periods up to an hour. Their first line of defence is it must be something to do with the kit in our house. But the rest of our kit (including work machines connected to different company servers etc) was all working when my personal email stopped.

When we move, I'm going to try to persuade my partner to have Plusnet. I was a long term happy customer.
MisterW
Superuser
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Registered: ‎30-07-2007

Re: relay.plus.net not working?

So it would have journeyed via the router and Sky before hitting O2 and/or Plusnet

Not quite, it would go nowhere near O2. It just means that all your access to relay.plus.net would have been through the single Sky IP. It would have been to believe that both the O2 and the SKY IP's were simultaneously blacklisted but now we know that in fact everything was bein sent using the single SKy IP , its quite likely that it was blacklisting that caused the problem. 

Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.