Emails suddenly no longer sending

[#1]

Noticed that I can suddenly no longer send emails through either my K-9 phone email client (5G or wifi) or my PC (WLM).

On my phone client I get two simultaneous notifications - 1 "Failed to send some messages ... authentication rejected as source IP has a poor reputation" and 2 "Authentication failed for .... Update your server settings".

On WLM it has started to ask for my logon details for the outgoing server (and not accepting them) even though set to be the same details as the incoming server, which does appear to be working.

Webmail working fine.

Any ideas?

[#2]

I had this problem from first thing this morning. Webmail is working.

[#3]

Having similar for a few days.

Too random to be a setting my end, just 50% to 75% fail rate for finding mail.plus.net and a proportion of my other mail and usual web sites.

Meanwhile a lot of others run fine - eg plusnet community website so i can post this, while the main portal site is a bit flaky.

Not too sure what the various bits in tracert mean, but seems to run into the sand getting out of BT/Plus back onto the internet - see attached

[#4]

Now sending via 5G but not through ISP ( Vodafone) .

[#5]

Which email brand folks?

[#6]

Force9

the clients are gmail on the Samsung and Apple Mail on the iPad 

[#7]

Are you logging in using your email address or using your account name?

This might be helpful...

Brand: Force9 - encryption supported: Yes

• IMAP: imap.force9.net port: 993 TLS/SSL
• POP3: mail.force9.net port: 995 TLS/SSL
• SMTP: relay.force9.net port: 587 STARTTLS

curl.exe -v imaps://imap.force9.net -u userID
curl.exe -v pop3s://mail.force9.net -u userID
curl.exe -v smtp://relay.force9.net:587 -u userID --ssl-reqd

The above are the correct server settings and diagnostic cURL tests.  Run the diagnostic test in a POWERSHELL window, replacing userID with your accountname - type the password when prompted - it is NOT echoed back.

[#8]

It's the userid+mailbox I'd and password. 

As for curl I'll have to try that when I'm back home in front of a PC.

[#9]

Plusnet email, in my case a free legacy account following migrating broadband many years ago.

Further testing on my laptop - connected to Vodafone using Thunderbird, sending fails with the following sequential notifications 1. - Login to server relay.plus.net with username username+mailbox failed and Sending of the message failed.
2. Unable to authenticate to Outgoing server (SMTP) relay.plus.net. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'.

Switch to mobile wifi hotspot (Three network) - sending succeeds with no settings in Thunderbird altered.

These settings are currently port 587, no connection security, authentication password transmitted insecurely.

Also tested with using STARTTLS port 587, same result.

I'm guessing that Vodafone IP's are currently being rejected by Plusnet's SMTP server

[#10]

Run the following in a POWERSHELL window.  Replace userID with your logon name, enter the password when prompted (it does not echo back to the console).  This should give you a very clear error message.

curl.exe -v smtp://relay.plus.net:587 -u userID --ssl-reqd

[#11]

As of 5pm the sending problems resolved simultaneously on all devices, I expect that the temporary IP block on Vodafone has expired.

[#12]

---

@Townman wrote:

Which email brand folks?

---

Mine is a plusnet address that is down to about 5% success rate on recieve

curl for pop3 gives:

PS C:\Users\new> curl.exe -v pop3s://mail.plus.net -u username
Enter host password for user 'username':
* Host mail.plus.net:995 was resolved.
* IPv6: (none)
* IPv4: 217.46.26.28, 217.46.26.48, 217.46.26.23, 217.46.26.13, 217.46.26.33, 217.46.26.38, 217.46.26.18, 217.46.26.43
*   Trying 217.46.26.28:995...
* connect to 217.46.26.28 port 995 from 0.0.0.0 port 57089 failed: Timed out
*   Trying 217.46.26.48:995...
* connect to 217.46.26.48 port 995 from 0.0.0.0 port 57091 failed: Timed out
*   Trying 217.46.26.23:995...
* connect to 217.46.26.23 port 995 from 0.0.0.0 port 57098 failed: Timed out
*   Trying 217.46.26.13:995...
* connect to 217.46.26.13 port 995 from 0.0.0.0 port 57100 failed: Timed out
*   Trying 217.46.26.33:995...
* connect to 217.46.26.33 port 995 from 0.0.0.0 port 57101 failed: Timed out
*   Trying 217.46.26.38:995...
* connect to 217.46.26.38 port 995 from 0.0.0.0 port 57110 failed: Timed out
*   Trying 217.46.26.18:995...
* connect to 217.46.26.18 port 995 from 0.0.0.0 port 57114 failed: Timed out
*   Trying 217.46.26.43:995...
* connect to 217.46.26.43 port 995 from 0.0.0.0 port 57116 failed: Timed out
* Failed to connect to mail.plus.net port 995 after 168682 ms: Could not connect to server
* closing connection #0
curl: (28) Failed to connect to mail.plus.net port 995 after 168682 ms: Could not connect to server

connecting to my other addresses, which are on stackmail, are about 20% success.  I don't send much but those are also flaky but could not give s % age

[#13]

connect to 217.46.26.28 port 995 from 0.0.0.0 port 57089 failed: Timed out

Has been seen before in connection with NORDVPN - see https://community.plus.net/t5/Tech-Help-Software-Hardware-etc/Outlook-cant-send-email-when-using-Nor...

Also https://community.plus.net/t5/Email/Authentication-Error/m-p/2003449#M48956

Are you using a VPN service?

Three entirely different issues on this thread...

• @mwwagain Plusnet looks like a NordVPN issue
• @Stuart22  Plusnet looks like a bad IP address with a third party ISP (resolved)
• @dalegilbert Force9 looks like two issues which are under investigation

[#14]

No VPN in use.

Using 'what is my IP' I get my expected plusnet static IP

AV is Zonealarm but no improvement with it off

[#15]

Ah dear old Zonealarm - used to be my go to firewall 20 years ago!!

Are you running Threat Emulation?  I'm wondering if that is 'getting in the way'.

The message reported by cURL does not show a source IP address, where it ought to.  That is the symptom of the NordVPN scenario - it is sending a 0.0.0.0 network address to the server.