Corp_Jones
asked on
address 550 Sender verify failed SMTP Error
Hi Guys
A User was getting the below bounceback sending to some servers:
This is the mail system at host out03.mx.trendmicro.eu.
"I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<xx@xx.com>: host mail.xx.com[x.x.x.x] said:
550-Verification failed for <my@exchangeserver.com>
550-Unrouteable
address 550 Sender verify failed (in reply to RCPT TO command) "
I initially thought it was a misconfigured SMTP smarthost so I Switched them over to Trend Micro hosted spam filtering (which includes outbound filtering via a smarthost) but they still get the same bounceback.
The server is SBS 2003 (which uses Exchange 2003), exchange is configured to forward all outbound e-mail to a smarthost (trend) which works fine for the most part, the virtual SMTP server is restricted to talking to only Trends servers if thats relevent.
I'm guessing theres something wrong with their domain/DNS but i've never seen this error, any ideas what to look for?
Thanks
A User was getting the below bounceback sending to some servers:
This is the mail system at host out03.mx.trendmicro.eu.
"I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<xx@xx.com>: host mail.xx.com[x.x.x.x] said:
550-Verification failed for <my@exchangeserver.com>
550-Unrouteable
address 550 Sender verify failed (in reply to RCPT TO command) "
I initially thought it was a misconfigured SMTP smarthost so I Switched them over to Trend Micro hosted spam filtering (which includes outbound filtering via a smarthost) but they still get the same bounceback.
The server is SBS 2003 (which uses Exchange 2003), exchange is configured to forward all outbound e-mail to a smarthost (trend) which works fine for the most part, the virtual SMTP server is restricted to talking to only Trends servers if thats relevent.
I'm guessing theres something wrong with their domain/DNS but i've never seen this error, any ideas what to look for?
Thanks
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Do you have a SPF record for the domain? Does the SPF include the smarthost server for sending mail?
command prompt:
nslookup -q=txt example.com
Shaun
command prompt:
nslookup -q=txt example.com
Shaun
ASKER
Thanks Shaun, tried that for the problem domain and I got:
"*** No text (TXT) records available for mydomain.com" so it looks like there is no SPF record
"*** No text (TXT) records available for mydomain.com" so it looks like there is no SPF record
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ASKER
Domain is foxclublondon.com
my understanding was that ptr records are not needed when using a smarthost. In this case I'm using trends outgoing server as smarthost which would have correct ptr record, is this not correct?
my understanding was that ptr records are not needed when using a smarthost. In this case I'm using trends outgoing server as smarthost which would have correct ptr record, is this not correct?
No, if you use a smarthost for outbound you don't need to worry about PTR/rDNS entries.
I would speak to trend about this issue, as you use them for inbound and outbound mail, and your domain looks fine, I'd speak to them about it.
Shaun
I would speak to trend about this issue, as you use them for inbound and outbound mail, and your domain looks fine, I'd speak to them about it.
Shaun
ASKER
Hmm, it can't be trend though as our other smarthost (ISP) had exactly the same issue
I'm a bit confused. So just to make sure I understand.
The 550 message is coming from the recipient's SMTP server, right?
If it is coming from the recipient's SMTP server, does that SMTP server always reject your e-mail, or does it just do it sometimes?
The 550 message is coming from the recipient's SMTP server, right?
If it is coming from the recipient's SMTP server, does that SMTP server always reject your e-mail, or does it just do it sometimes?
ASKER
Its always rejected from certain peoples SMTP servers
If possible I would try and contact at least one or two of them and see if they can tell you why they are rejecting you.
Although I will say I still think the smarthost needs a PTR record that points back to your domain.
If their SMTP server does a reverse lookup on the smarthost's IP address it expects a response and that response should include your domain.
Although I will say I still think the smarthost needs a PTR record that points back to your domain.
If their SMTP server does a reverse lookup on the smarthost's IP address it expects a response and that response should include your domain.
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If a mail server is configured to reject mail because the PTR does not contain the email domain name it is badly misconfigured and it needs fixing.
Think about every 'hosted email solution' on earth (rackspace, google apps, microsoft online, smtpauth.com) - no mail could be sent from them at all because the hosting companies MTA wouldn't contain the customers domain. Also, no mail could be sent from any smarthost in the world as they don't contain the customers domain.
Basically, smarthosts and email hosting would be impossible if the receiving server rejected on this criteria.
The PTR record SHOULD match the EHLO greeting, but it doesn't need to match the sending email domain in any way, same reasons as above.
Shaun
Think about every 'hosted email solution' on earth (rackspace, google apps, microsoft online, smtpauth.com) - no mail could be sent from them at all because the hosting companies MTA wouldn't contain the customers domain. Also, no mail could be sent from any smarthost in the world as they don't contain the customers domain.
Basically, smarthosts and email hosting would be impossible if the receiving server rejected on this criteria.
The PTR record SHOULD match the EHLO greeting, but it doesn't need to match the sending email domain in any way, same reasons as above.
Shaun
ASKER
Was other end and not our server/domain, not sure what they did but it sorted out the issues.
ASKER