topic Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy) in Email

Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Sun, 04 May 2025 20:11:03 GMT

I've recently encountered a problem where I am unable to send email when on WiFi (when connecting via mobile data all works ok).

I receive the following error:

READ May 04 20:41:42.341 [kCFStreamSocketSecurityLevelTLSv1_2] -- host:relay.plus.net -- port:465 -- socket:0x600000e21020 -- thread:0x600007e07540
554 avasout-peh-001 smtp ESMTP server not available (blacklisted by local policy)

I have a static IP: 84.92.112.184

Using this link: https://mxtoolbox.com/blacklists.aspx - I can see that "Spamhaus ZEN" &
"Sender Score Reputation Network" have my IP blacklisted.

How do I go about resolving this issue?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

Townman — Sun, 04 May 2025 21:55:55 GMT

Disconnect your router for around 2 hours then reconnect. That should get you a different IP address.

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

RealAleMadrid — Mon, 05 May 2025 06:45:14 GMT

@Townman I don't think so, the Op has a static IP address.🙄

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Mon, 05 May 2025 06:51:00 GMT

@bornmild I think @Townman missed the I have a static IP: 84.92.112.184 in your post. In his defence he has been putting in a lot of time here developing some test procedures to help with the upcoming email migration project.

Anyway back to your problem, as you probably realise , disconnecting will not give you a new IP since its static.

I assume you've had the static IP for some time as its not possible to get a new one allocated.

Do you send large volumes of mail ?

BTW you seem to be using port 465

READ May 04 20:41:42.341 [kCFStreamSocketSecurityLevelTLSv1_2] -- host:relay.plus.net -- port:465 --

that's depracated, you should be using 587 and STARTTLS

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Mon, 05 May 2025 08:17:59 GMT

Thanks for the responses @Townman & @MisterW

Yes, I have a static IP and I have so for some years (possibly 10+ years)

No, I don't send high volumes of email - a maximum of 5 a day.

I've updated my settings but I still see the same error?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

Gandalf — Mon, 05 May 2025 08:36:09 GMT

You should be able to request the IP is removed from the blocklists by going here although I’d first run through the checks they advise for preventative measures.

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Mon, 05 May 2025 08:50:05 GMT

I've updated my settings but I still see the same error?

Yes, sorry if I wasn't clear, I didnt expect that to fix it but its more correct to use 587.

Do you send email from a hosted domain address or from your native <account>.plus.com address ?

~~Looking up on another blacklist checker , I dont think youre actually still on the zen spamhaus any more.~~

The sender reputation one is a bit more difficult to check directly since they insist on providing details beore you can check

You could try their site directly https://senderscore.org/

Since you have a low volume of mail , maybe you've just got a very low reputation and if you somehow got tagged by a recipient or managed to send mail to a spam honeypot then the reputation may have gone negative ?

@Gandalf thanks for that. Some of the 'technical information' from there looks a bit 'odd'

@bornmild are you running an smtp server on any of your devices ?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

Townman — Mon, 05 May 2025 09:00:35 GMT

Doh!! Sorry need to read more carefully.

What am I missing here … I thought spamhaus zen black listing by local policy is all related to running one’s own SMTP server rather than using Plusnet’s. We have seen third party email services misuse that black list elsewhere.

Though if IRRC we have also seen a Plusnet SMTP server on the “wrong side of the fence”.

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Mon, 05 May 2025 09:17:22 GMT

Thanks again for the responses.

I send email from a hosted domain (hosted by 123Reg).

I don't run a smtp server on any of my devices. (that I'm aware of)

According to senderscore my sender reputation is "POOR"

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Mon, 05 May 2025 09:34:38 GMT

I send email from a hosted domain (hosted by 123Reg).

Do you have an SPF record on your domain that allows sending via relay.plus.net ?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Mon, 05 May 2025 10:15:59 GMT

I don't believe I have a SPF record set.

I can see a section on 123Reg where I can add DNS records... do I need to add a record of type TXT?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Mon, 05 May 2025 10:28:04 GMT

Yes, assuming you only send via the Plusnet servers, you need to add a TXT record as follows

v=spf1 a mx include:_spf-internal.plus.net include:_spf-internal2.plus.net ~all

However , I'm not sure that's going to fix the immediate problem. Having set the SPF record, you probably need to go through the spamhaus link that Gandalf posted earlier and request removal. The sender score reputation should improve now the SPF is set, but how long that may take ?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Mon, 05 May 2025 10:41:43 GMT

Thanks again - you've been incredibly helpful

I've added the SPF record and have requested spamhaus to delist my IP - I guess I now need to wait for these changes to propagate...

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Tue, 06 May 2025 09:10:29 GMT

My IP has been removed from Spamhaus' CSS Blocklist.

But 24 hours on I'm still getting the following error:

READ May 06 10:03:39.859 [kCFStreamSocketSecurityLevelNone] -- host:relay.plus.net -- port:587 -- socket:0x6000023a30c0 -- thread:0x600001905a80
554 avasout-ptp-004 smtp ESMTP server not available (blacklisted by local policy)

Is there anything else I or Plusnet can do? Or do I have to just wait?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Tue, 06 May 2025 09:17:12 GMT

what does senderscore say for your reputation now ?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Tue, 06 May 2025 09:23:30 GMT

Unfortunately, my senderscore is still "0:POOR"

I'm not sure how/if/when that would get updated?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Tue, 06 May 2025 09:42:12 GMT

I'm not sure when that will updated either ?

Did you look at the 'more info' when checking your IP on the spamhaus site ?

The HELO values shown seem strange , apart from the one showing your correct <account>.plus.com ?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Tue, 06 May 2025 09:56:30 GMT

Yes, those HELO values do look strange... I don't know where those others are coming from 😬

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

MisterW — Tue, 06 May 2025 10:07:17 GMT

As Spamhaus suggest checking , is there ANY possibility that one of your devices has malware ?

Re: Cannot send email: smtp ESMTP server not available (blacklisted by local policy)

bornmild — Tue, 06 May 2025 11:11:21 GMT

I shall do another deep scan... starting with my teenagers devices 🙄

Can I set any further firewall rules on my Plusnet Two Hub router which may help block malicious activity?