on 16-01-2020 10:35 AM
I'm using Pipex DSL email and processing Microsoft Office Pro 2016.
Using Outlook, I have one important email sender who, suddenly is unable to send emails to my email address, it has been working for a long time.
The error - 503 Bad sequence of commands.
I have made various changes to my email settings, I believe they are correct and up to date. The sender has spoken to his support and also believes his system is correct and up to date.
This error only occurs with this sender who lives in France.
Any help and advice would be very useful. Thank you.
on 21-01-2020 12:14 AM
Thanks for the contribution to this topic. It's useful to know the exact sender and it may help to know that mout.kundenserver.de is on some spam blacklists including SORBS NEW and SORBS SPAM. So Ionos may have some reputation building to do before delisting happens. SORBS NEW indicates recent spam detection in the last 2 days.
This would explain a rejection of messages from the Ionos server mentioned but not necessarily the class of error message.
on 20-01-2020 06:38 PM
I have exactly the same problem with my pipex email. Two apparently unconnected senders have been unable to send email to me since 6th or 7th Jan. I have been communicating with both for some years without any problems.
My senders have seen various rejections including 503 Bad sequence of commands, and messages implying the recipient doesn't exist. I've now discovered both senders use 1and1/ionos. Headers from messages received before the problem started show their outgoing email server is mout.kundenserver.de
So it seems like this could be a problem specific to 1and1/ionos senders. Really need this to be fixed ASAP.
on 20-01-2020 07:25 AM
Thanks Teapot, I've raised a fault ticket for you. Please chase in 3 working days if you've not already had an update.
on 18-01-2020 10:08 AM
Apologies, I'd seen you were using the dsl.pipex platform. No TalkTalk mailbox in addition to pipex?
I'll ask OCE_Ady to pick this up on Monday. He has contact with the team looking at network filtering issues just to see if this particular issue is a side effect of how that filtering is working.
Please do a quick check that your Community Profile includes in Personal Information (Click here) in Private notes at the bottom of the page your pipex email address and your friend's ionos email address with any relevant other notes and finally save changes.
on 18-01-2020 09:36 AM
Staying with webmail, what is the error message your French friend sees using webmail?
It's unlikely to be the 503 error or other authentication error. More likely to be your mailbox rejecting the incoming message - but if so there should be a more specific error message such as being rejected because of content.
Please sign in to TalkTalk Mail here and check that you have no Filter rules that are blocking or redirecting the incoming message.
The above is to ensure your mailbox is having no effect upon the incoming mail message.
on 17-01-2020 10:14 AM
Hi teapot, it looks like Gondola has got your issue in hand. Please let us know how you get on.
17-01-2020 09:27 AM - edited 17-01-2020 11:01 AM
Ionos (fr) does have some very helpful advice. In particular about authentication for sending email from the Ionos outgoing server.
The advice does say use TLS / STARTTLS with port 587 although you can use Auto.
I don't see where it says not to use STARTTLS. (Although if they use SSL the port number is 465)
What happened when you both tried webmail to send and receive mail messages?
on 17-01-2020 06:46 AM
Information from France...
Outgoing server requires authentication – ticked.
Advanced – this server requires encrypted connection (SSL) On 1&1 (IONOS) we are instructed not to use STARTTLS
The problem still exists.
on 16-01-2020 03:16 PM
It'll depend if the error message is being returned by the sender's smtp server or the pipex server.
The most usual reason for the 503 bounceback is that the mail message is not being authenticated by the sender's network. You'll usually see in Outlook a setting My outgoing server (SMTP) requires authentication. That or the equivalent needs to be enabled on your sender's email client.
You could troubleshoot the issue by both parties using webmail to prove you can exchange mail messages. Then check that both email clients are using SSL/TLS encryption / connection security with network authentication.
TalkTalk mail client settings are given in the help page Email settings - IMAP & POP3. Your sender will need to check with their mail service provider for their recommended secure email settings.