Resolved Error 550 5.7.26 sending Mail with mailenable from windows server with plesk obsidian

[Bricee]

Server operating system version

Microsoft Windows Server 2016 x86_64

Plesk version and microupdate number

Plesk Obsidian 18.0.52.3

Hello everyone
I am suddenly getting bounce backs from gmail recipients. I have Use DKIM spam protection system to sign outgoing email messages ticked in the domain panel.
Can anyone explain what may have changed?

Many Thanks

 

[Peter Debik]

Does your domain have a valid SPF entry?

 

[SDGPete]

Copy of MailEnable SMTP logs would be helpful

 

[Bricee]

Does your domain have a valid SPF entry?

Hello Peter
Thanks for answering - this is all new stuff to me
it has two SPF entries -
v=spf1 +a +mx +a:SAU-48AEF-VS.servercontrol.com.au -all
v=spf1 mx a ptr -all (This one has a yellow ! next to it)

 

[Bricee]

Copy of MailEnable SMTP logs would be helpful

Hello SDGPete - thanks for your help.
These are the only files I can find for MailEnable. Located in C:\Program Files (x86)\Mail Enable\Logging\SMTP on our server. Is this what you are asking for?
Please excuse my ignorance as this is all new to me.

 

[Bricee]

Hello Peter
Thanks for answering - this is all new stuff to me
it has two SPF entries -
v=spf1 +a +mx +a:SAU-48AEF-VS.servercontrol.com.au -all
v=spf1 mx a ptr -all (This one has a yellow ! next to it)

hello Peter - here is bounce back text

MailEnable: Message could not be delivered to some recipients.
The following recipient(s) could not be reached:

Recipient: [SMTP:[email protected]]
Reason: 550-5.7.26 This mail is unauthenticated, which poses a security risk to the

550-5.7.26 sender and Gmail users, and has been blocked. The sender must

550-5.7.26 authenticate with at least one of SPF or DKIM. For this message,

550-5.7.26 DKIM checks did not pass and SPF check for [p2d.org.au] did not pass

550-5.7.26 with ip: [221.121.143.142]. The sender should visit

550-5.7.26 Prevent mail to Gmail users from being blocked or sent to spam - Gmail Help for

550 5.7.26 instructions on setting up authentication. r201-20


Message contents follow:

DKIM-Signature: v=1; c=relaxed/relaxed; h=to:from:subject:date:message-id:mime-version:content-type;
d=p2d.org.au; s=default; a=rsa-sha256;
bh=bMzeGla9Lz14UdRAHWl61Ook2rZRLpmBPBcSXHgJCIo=;
b=gEczwwzoVdGNj1TqDV3u4JbbhMwQmduew0BZ+VqldFjz6zXgvFatZh6jdZzCV/ync
j0Ym4PZ0jjazSllcLisG2Psd5fOFxkfGXXsYNneT8Zt85pjLoBjqBYpaICRyHfYsvqr
9ZAShDwXh7xQBhbbVha7/asve9pZLkBK1rRUF/8=;
Received: from ([180.150.90.120]) by home with MailEnable WebMail; Thu, 1 Jun 2023 09:50:53 +0800
To: <[email protected]>
From: "Max Williams" <[email protected]>
Subject: test
Date: Thu, 1 Jun 2023 09:50:53 +0800
Message-ID: <F94E050406774807BF109E4E86BC87C8.MAI@home>
MIME-Version: 1.0
X-MimeOLE: Produced By MailEnable WebMail.NET V2.0.0.0
X-Mailer: MailEnable WebMail.NET
Content-Type: multipart/alternative;
boundary="__=_AltPart_2139359324_1995236873"

This is a multi-part message in MIME format.

--__=_AltPart_2139359324_1995236873
Content-Type: text/plain;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable


test

--__=_AltPart_2139359324_1995236873
Content-Type: text/html;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div style=3D"font-size: 12pt;">test</div>




--__=_AltPart_2139359324_1995236873--

 

[Bricee]

Copy of MailEnable SMTP logs would be helpful

here is bounce message text


MailEnable: Message could not be delivered to some recipients.
The following recipient(s) could not be reached:

Recipient: [SMTP:[email protected]]
Reason: 550-5.7.26 This mail is unauthenticated, which poses a security risk to the

550-5.7.26 sender and Gmail users, and has been blocked. The sender must

550-5.7.26 authenticate with at least one of SPF or DKIM. For this message,

550-5.7.26 DKIM checks did not pass and SPF check for [p2d.org.au] did not pass

550-5.7.26 with ip: [221.121.143.142]. The sender should visit

550-5.7.26 Prevent mail to Gmail users from being blocked or sent to spam - Gmail Help for

550 5.7.26 instructions on setting up authentication. r201-20


Message contents follow:

DKIM-Signature: v=1; c=relaxed/relaxed; h=to:from:subject:date:message-id:mime-version:content-type;
d=p2d.org.au; s=default; a=rsa-sha256;
bh=bMzeGla9Lz14UdRAHWl61Ook2rZRLpmBPBcSXHgJCIo=;
b=gEczwwzoVdGNj1TqDV3u4JbbhMwQmduew0BZ+VqldFjz6zXgvFatZh6jdZzCV/ync
j0Ym4PZ0jjazSllcLisG2Psd5fOFxkfGXXsYNneT8Zt85pjLoBjqBYpaICRyHfYsvqr
9ZAShDwXh7xQBhbbVha7/asve9pZLkBK1rRUF/8=;
Received: from ([180.150.90.120]) by home with MailEnable WebMail; Thu, 1 Jun 2023 09:50:53 +0800
To: <[email protected]>
From: "Max Williams" <[email protected]>
Subject: test
Date: Thu, 1 Jun 2023 09:50:53 +0800
Message-ID: <F94E050406774807BF109E4E86BC87C8.MAI@home>
MIME-Version: 1.0
X-MimeOLE: Produced By MailEnable WebMail.NET V2.0.0.0
X-Mailer: MailEnable WebMail.NET
Content-Type: multipart/alternative;
boundary="__=_AltPart_2139359324_1995236873"

This is a multi-part message in MIME format.

--__=_AltPart_2139359324_1995236873
Content-Type: text/plain;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable


test

--__=_AltPart_2139359324_1995236873
Content-Type: text/html;
charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div style=3D"font-size: 12pt;">test</div>




--__=_AltPart_2139359324_1995236873--

 

[Peter Debik]

Please remove the additional SPF entry an only use

v=spf1 a mx a:<your hostname> -all

Omit the "+" signs, too.

 

[Bricee]

Please remove the additional SPF entry an only use

v=spf1 a mx a:<your hostname> -all

Omit the "+" signs, too.

I have done as you described but mail to gmail accounts is still failing.
I have attached an image of my DNS settings as they are now. Does this look correct.

 

[Bricee]

I have done as you described but mail to gmail accounts is still failing.
I have attached an image of my DNS settings as they are now. Does this look correct.

Please remove the additional SPF entry an only use

v=spf1 a mx a:<your hostname> -all

Omit the "+" signs, too.

OK its all working correctly now. Thank you so much Peter.

 

[SDGPete]

Hi @Bricee I'm not sure it is working, the domain of the FROM email address (p2d.org.au) doesn't have an SPF record (Lookup - SPF-Record). This is likely to be blocked by GMail.

Create a TXT record for the domain and add the following in your value field (including the quotes)

"v=spf1 a mx ?all"

The screenshot of your DNS looks to be from Plesk but your nameservers/DNS for the domain is listed as nameserver.net.au are you sure the Plesk DNS is your actual active DNS? If it's not then the TXT records you have added wont be active.

 

[Bricee]

Hi @Bricee I'm not sure it is working, the domain of the FROM email address (p2d.org.au) doesn't have an SPF record (Lookup - SPF-Record). This is likely to be blocked by GMail.

Create a TXT record for the domain and add the following in your value field (including the quotes)

"v=spf1 a mx ?all"

The screenshot of your DNS looks to be from Plesk but your nameservers/DNS for the domain is listed as nameserver.net.au are you sure the Plesk DNS is your actual active DNS? If it's not then the TXT records you have added wont be active.

Hi SDGPete
Thanks for your reply - my mail has been flowing again properly but I added the record at the domain record as per your suggestion and the SPF record check still fails? Any suggestions most appreciated

 

[SDGPete]

Hi @Bricee unfortunately I'm still not seeing a public SPF record for your domain, this furthers my thought that the DNS you've been editing is not the DNS for the domain.

Your DNS nameservers for p2d.org.au are
ns3.nameserver.net.au
ns1.nameserver.net.au
ns2.nameserver.net.au

This looks (my best estimate) to be provided by Homepage - Main, the domain name p2d.org.au was also registered through that provider. If I'm correct, login to that provider Homepage - Main and edit the DNS there to include the SPF TXT record.

"v=spf1 a mx ?all"

If the domain also sends via SAU-48AEF-VS.servercontrol.com.au server then include that too.

"v=spf1 a mx a:SAU-48AEF-VS.servercontrol.com.au ?all"

 

[Bricee]

Hi @Bricee unfortunately I'm still not seeing a public SPF record for your domain, this furthers my thought that the DNS you've been editing is not the DNS for the domain.

Your DNS nameservers for p2d.org.au are
ns3.nameserver.net.au
ns1.nameserver.net.au
ns2.nameserver.net.au

This looks (my best estimate) to be provided by Homepage - Main, the domain name p2d.org.au was also registered through that provider. If I'm correct, login to that provider Homepage - Main and edit the DNS there to include the SPF TXT record.

"v=spf1 a mx ?all"

If the domain also sends via SAU-48AEF-VS.servercontrol.com.au server then include that too.

"v=spf1 a mx a:SAU-48AEF-VS.servercontrol.com.au ?all"

Hello Again SDGPete
You were on the money!! The Domain is hosted at VentraIP and the relevant DNS records are there. I have updated as per your suggestion.
Many thanks for persisting with this as it has taught me a valuable lesson. Waiting for record to resolve then will test again with spf lookup.

 

[SDGPete]

@Bricee glad you got it sorted!