Getting "recipient rejected - relay denied" sending to own account on force9 (for copy-self)

[#1]

I have been having a problem with my copy-self setup when sending emails, and have managed to reproduce it in a simple form.

When sending an Email from an account to the same account, the client comes back with an error message:

From: xxxx@xxxx.f9.co.uk

To:     xxxx@xxxx.f9.co.uk  (i.e. same account as From:)

Thunderbird gives this error message, and doesn't send:-

"An error occurred while sending mail. The mail server responded:
<xxxx@xxxx.f9.co.uk> recipient rejected - relay denied.
Please check the message recipient "xxxx@xxxx.f9.co.uk" and try again.  [OK]  "

Using Webmail to send a message to myself DOES work.

As I said, this problem has been seen using copy-self to get copies of sent mail which can then be read on another device if necessary (i.e. the example above is just a simple way to reproduce the problem). I have been using the same method of doing copy-self for years, and it has only given this error in the last few weeks. I would appreciate some help working out whether Thunderbird is a part of the problem (but it seems to be just reporting a status from the server?).

Could it have anything to do with Spam prevention on the server? OK it's not the end of the world, but I'd like to get it working again if possible, so help is appreciated.

I am using Thunderbird 68.7.0 (32-bit) on Windows 8.1.  The problem is seen on my desktop connected to force9 broadband.

[#2 · Accepted solution]

Can you send OK to other addressees?

[#3]

Thanks for your input, it helped.

The problem was due to my being connected via a VPN (on my Force9 broadband). Presumably to do this, I would need authentication setting in my email client for the outgoing Server. Or I can disconnect from the VPN so that I am "local" to plusnet/force9.

Dave

[#4]

Hi Dave,

You would be correct.  If you are attempting to connect to Plusnet services over a VPN, then you are in effect connecting from an alien network.  Therefore the SMTP server configuration must be authenticated.

Also remember to select encryption - SMTP should be port 587 with "STARTTLS" or you could use the deprecated option on port 465 using "SSL/TLS".

[#5]

I ran into the same problem as soon as I started using VPN on my PlusNet link, and ended up staying awake past 2am trying to figure out why it was happening, till I realised VPN was the culprit.  As Townman says, when VPN is on, you are treated as if you were on an 'alien' (non-PlusNet) network.  You can obviously get round this by switching off VPN while your email is sent out (which may not suit you, since the very purpose of VPN is to stop your internet traffic being sniffed, and also because you may then forget to switch it back on) OR by changing your mail account settings such that you have to authenticate yourself to the SMTP server relay.plus.net whenever you send. If you do neither of these, then you will get the 550 error message you mentioned.

My reason for joining in here is that the second solution above (SMTP authentication) is still not a very good one, because PlusNet then will place severe restrictions on your outgoing email traffic, as I have found when away from home and therefore not using my PlusNet broadband link.  If you try to send  through your email client what PlusNet considers (at its sole discretion) to be too many emails (including even perhaps just one email to a lot of recipients) you can find that you get a PlusNet message back saying the email was not sent – the detail of which I cannot remember, not even the error message number (sorry). The thinking behind it is that you are potentially a spammer trying to make use of PlusNet’s SMTP servers. I had this matter out with PlusNet when I was abroad and using Outlook client to send emails. I had grasped that I needed to use SMTP server authentication and had configured that in, but then encountered the other error message (indicating too many emails sent) after sending very few emails. The worst of it is that you don’t even get that message straight away after sending, and as far as I recall, it is difficult to know exactly which of your emails did not get sent. Once this restriction has set in, you have to refrain from sending more emails for some long period (maybe an hour) till it lifts the complete barrier – a right pain, as I found when trying to send Christmas messages while away. I also got the impression that the restriction got tighter the more times PlusNet considered you to have offended – I do recall once giving up and leaving my emails till the next day before sending – but that could just have been my impatience and exasperation kicking in.

I have recently raised* this matter with PlusNet, because it is not good that I have to switch off the VPN while sending, nor can I put up with the restriction on email volumes when Plusnet 'thinks' I’m on an alien network.  I will, as Townman suggested to you, look at using email encryption and port 587, but the email account parameters I am using are those that that PlusNet guidance specified when I first started using PlusNet email (yonks ago).

Is there truly no way for PlusNet's SMTP to determine that I am on a PlusNet link when I use VPN?  I am sure Kevin will know the answer...

 - - - -

* (and PlusNet Support person's response was that the recipient's email address (my own) did not exist.  I have replied as politely as I could, asking for someone who understands the matter to look into it.

[#6]

Oh and by the way...

If you do switch off VPN while sending, do take account of the fact that sending may take quite a long time particularly if the email is large (e.g. with sizeable picture attachments) and/or you have a virus-checker (I have Norton 360) processing them on the way out.  If you turn the VPN back on too soon, you may then get an error popping up saying that the connection to the email server was interrupted and you need to send the message again. (Sigh / 🙄 / 🤐)

[#7]

"Is there truly no way for PlusNet's SMTP to determine that I am on a PlusNet link when I use VPN?"

------------------------

In a word no!  The whole point of using a VPN is to hide who you are and where you are from the outside world.  TO some extent the VPN acts like the NAT in the home router.  You device will be 192.168.1.x but the outside world only sees your external IP address.

In respect to rate limiting, if the VPN service is hosted overseas, then email submission rate will be subject to the off-shore submission limits, the details of which (for understandable reasons) are not in the public domain.  Conversely, if the VPN is hosted within the UK, the submission rate will be profiled less aggresively.

[#8]

"The whole point of using a VPN is to hide who you are and where you are from the outside world"

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I think you use "whole point" loosely.  For me, and I suspect for majority of users, it's mainly about encrypting the traffic to stop it being intelligible to sniffers.  One purpose may be to conceal the user IP address and location   (e.g.. to work around geographically-restricted content), but I was hoping (in vain, it seems) that there was something in there at least that would enable PlusNet to know it is a PlusNet network talking.  Given what you say, it appears I bought a double-edged knife and have pressed down on the blade while cutting the Cheddar.

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"In respect to rate limiting, if the VPN service is hosted overseas, then email submission rate will be subject to the off-shore submission limits, the details of which (for understandable reasons) are not in the public domain.  Conversely, if the VPN is hosted within the UK, the submission rate will be profiled less aggresively."

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That isn't something I had considered, and I have no idea where my Norton VPN is hosted, but the restrictions I encountered were back when I was not using a VPN and was in Central America.   They were quite severe.  But I have also run into them when sending email from my laptop PC in this country, using wifi and broadband via other people's home (non-PlusNet) networks (without VPN) and I think they were still pretty strict.

I will probably use VPN when abroad in future, especially on hotel wi-fi.  If it turns out that my VPN is UK-based, does that mean then that I will be better off in terms of email volume restrictions than if not using VPN?

[#9]

I'm guessing it should be.

As I said the details of the restricts are not disclosed, for knowledge of such might help some people thwart the effectiveness of the measures designed to protect the integrity of the email service for all users.

This topic https://community.plus.net/t5/Email/Too-many-rcpts-in-time-period-from-this-IP/m-p/1397146#M17851 makes reference to 6 emails (addressees?) per hour.  I recall one which gave more figures but cannot find it right now.

What that post has reminded me about, is that you can totally circumvent the rate submission limits by using webmail.

[#10]

I am not sure that using Webmail does get round the problem of email volume restrictions when working from abroad, and won't be able to test that till I next am abroad (if ever),  I did resort to it last time when fed up getting the "Too many rcpts in time period from this IP" messages when sending from Outlook, but only ever sent a handful via Webmail.

Anyway, reading your posts above has made me realise that the volume restrictions on emails sent via PlusNet are probably all to do with working from overseas, not from simply being on an alien network (or appearing to be so because of using a VPN).  My recollections of finding such restrictions when working from other people's homes in UK are, I now think, unreliable, and the instances I remember were quite possibly all from foreign climes.  The upshot is that (ahem) I was evidently talking poppycock when I said that getting around the VPN problem by using SMTP authentication would still leave the user with the problem of volume restrictions (my paragraph beginning "My reason for joining in here").  That may only be true if the user is abroad or is using a foreign-based VPN.  I have proved here that I know very little, so that could also all be wrong.

 I have now run some tests with VPN on, sending multiple emails from Outlook to multiple recipients (all ultimately diverted to me so as not to harass my contacts!), all emails having a large attachment, and did not run into any restriction at all.  It does therefore appear the restrictions (or at least tight ones) are only applied when the sender is working from abroad.  So, quite possibly, a UK-based VPN will actually be helpful if using an email client such as Outlook, as it may make it appear that I am working from UK.  Won't know till I try.  The VPN panel does say my current region (auto-selected) is UK, but does also allow manual selection, but what exactly that achieves or is for, I haven't yet checked. 

I probably therefore do not have a problem sending lots of emails via VPN from Outlook when at home, and will have to grovel and amend the ticket I raised.  I rashly assumed the very fact of appearing to be on a non-PlusNet network would precipitate the same restrictions I encountered when abroad.   [Note to self: find that note saying "Check facts before firing off complaint" and pin it up.]

A further finding of note... VPN appears to have a negative effect when working with Yahoo email.  On certain emails (e.g. ads from Microsoft), when I try to open them, I get a Windows error panel saying "b.gemini.yahoo.com’s server IP address could not be found".  Switch off VPN and they open up OK.  I'm stumped with that one.

[#11]

Sometimes things appear to be something they are not and when there are multiple layers in play, seeing what is critical to the experience can be difficult. Don’t be too hard on yourself. There are layers of restriction here to protect service integrity and when a VPN is added to the equation things might not be what they appear to be. Note that when using webmail, the SMTP connection (where the rate limiting is applied) sees the connection as being from the webmail service IP address ... which is always on the Plusnet network.

As for your last point, the issue should be raised with your VPN provider. It would seem that the Yahoo server in question does not appear to be in their DNS service. You might be able to mitigate the issue by placing a fixed address resolution for that server in your device’s hosts file. I’m rusty on how host file address resolutions interplay with the operation of VPN clients. I know that some configurations inhibit access to the local network, so I can imagine that local host address resolutions could also be inhibited. It’s worth a try.