IIS 5 & IIS 6
smtp;550 5.7.1 Connections not accepted from servers without a valid...
Last post Jan 11, 2011 11:59 AM by KristoferG
Jan 11, 2011 04:49 AM|gopalanmani|LINK
we are getting randomly Undeliverable message from System Administrator.
We are getting the following error,
The following recipient(s) cannot be reached: <firstname.lastname@example.org> on 1/3/2011 9:49 AM
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<P2036807 #5.7.1 smtp;550 5.7.1 Connections not accepted from servers without a valid sender domain.Fix reverse DNS for xxx.xxx.xxx.xxx>
How can i fix that error?
Jan 11, 2011 04:58 AM|KristoferG|LINK
Do you get this from other SMTP servers or your own?
Some SMTP servers require that the reverse DNS must match the domain name you are sending from. For example, when you send from
email@example.com, the domain name of your SMTP's IP address must be domainname.com. This is done to prevent spam from infected personal computers, sending spam with a local installed SMTP server.
You configure a reverse DNS by setting up a PTR record. This is however done by your ISP (or whoever owns the IP address), and you as a domain owner cannot do this. You need to ask your ISP.
Jan 11, 2011 09:00 AM|gopalanmani|LINK
Thank you for your response.
this is our own server and initially we are configured the DNS settings using our remote connection.
so how can we configure the reverse DNS in windows server? or is there any alternative solutions for that.
Jan 11, 2011 09:11 AM|KristoferG|LINK
Do you run your own DNS server?
You should have an option for "Reverse lookup zone" (i don't know the exact name at this moment). Use this to create a new zone. Then add a PTR record to that zone.
But as i said previously, this may not work. Your ISP may handle the reverse lookup for your IP address, which would make this pointless to do. I suggest that you check with your ISP and explain the problem: "I need a reverse DNS for my domain name, since
some SMTP servers does not accept our emails". They should know if they need to do anything, or if you can do this yourself (my guess is that your ISP must be involved in this).
Jan 11, 2011 09:20 AM|KristoferG|LINK
Or put in other words, do you own the IP address (registered in APNIC), or are you only provided Internet access by an ISP?
Jan 11, 2011 11:36 AM|gopalanmani|LINK
Hi Kristofer Gafvert,
Yes, we are run with our own DNS server and also using the own IP address.
Jan 11, 2011 11:59 AM|KristoferG|LINK
Then you should figure out what to do with the following articles: