All Questions
Tagged with email-server reverse-dns
48 questions
0
votes
2
answers
477
views
Why is PTR needed in DNS, instead of using a service record or an MX record?
Why would an organization with an email system have a requirement that a system sending email to it needs a PTR reverse lookup DNS record of the IP address of the sending email server?
Can the ...
- 101
0
votes
2
answers
917
views
Too many connect from unknown postfix
I am trying to set up an incoming email server by using postfix as MTA the issue I am facing is that there are too many 'connect from unknown' lines in the log. Can anyone help can I debug this issue? ...
- 205
1
vote
1
answer
659
views
How to add a PTR (Reverse DNS) on Vultr? Do I need to contact them?
I have set up a Postfix Dovecot email server on my Vultr. And I'm getting following message from Google:
gmail-smtp-in.l.google.com said: 550-5.7.1
Our system has detected that
550-5.7.1 ...
- 53
0
votes
3
answers
1k
views
How to avoid reverse DNS errors
I am running a mail server (Exim) on a VPS (Ubuntu 22.04 LTS). I am able to send and receive emails without problem, but I do get the following errors from mxtoolbox.com:
Reverse DNS does not contain ...
4
votes
3
answers
3k
views
Configuring a PTR record in domains.google for an SMTP server
I've found several threads related to this, but they are all very dated so I want to get some clarification.
I use an AWS ec2 instance with an elastic-ip, I've set up an SMTP (sendonly) mail-server ...
- 45
1
vote
1
answer
590
views
email validation: is there any point doing both SPF *and* reverse DNS tests?
For a receiving MTA, it seems to be unnecessary to check both the SPF record for an incoming SMTP connection, and to do an rDNS/PTR lookup.
Consider:
Server gets SMTP connection from aaa.bbb.ccc.ddd, ...
- 223
0
votes
0
answers
1k
views
Do I need a PTR (rDNS [Reverse DNS]) record if using an SMTP mail relay (Mailgun, Mailjet, Send Grid, etc.)?
My cloud hosting provider wants to charge for setting up a PTR record, which I'm not up for.
As I use Mailjet as an SMTP relay server, do I even need to have it setup? Or will all my emails reverse to ...
- 219
0
votes
1
answer
643
views
Using own bind name server allowing reverse dns for own mail server
I successfully created my own email server running on Ubuntu but other mail servers refuse incoming mails from my server because there is no reverse dns (PTR record).
The configuration looks like
own ...
- 103
0
votes
2
answers
2k
views
Running your own email-server for multiple domains on single IP
I'm doing a little research on how you can run your own e-mail server for your domain. I know that you can use Zoho, or gmail, or any other alternative. However, I'm wondering if it's possible to do ...
0
votes
1
answer
683
views
Can't send email to some servers
I get this error below, after I send email to some domains including charter.net
SMTP error from remote mail server after MAIL FROM:<******@mydomain.com>:
550 5.7.1 Connections not accepted ...
- 103
-5
votes
2
answers
677
views
domain name system - rDNS is not exist [closed]
I need some help with Reverse DNS as I have got a problem with it. I have setup rDNS on my hosting provider which I use rdns1.example.com and I have a server hostname which it is gateway1.example.com. ...
- 101
2
votes
1
answer
310
views
Having multiple A records to get forward rDNS to work
Running a Droplet on DigitalOcean with Apache and a mailserver on Ubuntu. I've managed to get SPF, DKIM and DMARC working on this server, but Reverse DNS is something that I've never figured out.
I ...
- 365
0
votes
1
answer
324
views
Delegating reverse dns records - Bind (Ubuntu Server)
I have got a mail server attached to a static provided by my ISP. Our dns service is run by buddyns DNS service because our ISP blocked 53 by default. The DNS service is excellent, but i dont know how ...
1
vote
1
answer
167
views
Reverse DNS and Mailserver and self generated certificates
this is my first question here, so don't kill me if it sounds stupid.
I don't know much about server administration, that's why we booked a managed server to host our clients.
So far we have been ...
- 13
26
votes
3
answers
4k
views
Has my ISP mangled my DNS reverse lookup record for a single static IP address?
I've taken on the task of running a small email server, and the world of spam makes it more challenging for an individual, as many MTAs are highly paranoid about accepting email.
I think I've ...
- 271
2
votes
2
answers
2k
views
Multiple mail servers and reverse DNS
If I have three mail servers MS1, MS2 and MS3 all with different IPs but share the same domain name (exampledomain.com) and I use an SPF record to specify them, how would reverse DNS work on the ...
- 43
5
votes
1
answer
12k
views
MXToolbox: "Reverse DNS is not a valid Hostname"
I know that there is another thread about this topic here on serverfault.com but it did not solve my issue.
I have also googled it and it seems that SPF record could be mis-configured in some cases ...
- 281
3
votes
1
answer
2k
views
How to set up mx records
So I bought a new domain name from GoDaddy and pointed the domain to my VPS IP Address which works fine.
[Please note, the VPS is not hosted with GoDaddy, just the domain name.]
However, I noticed ...
- 189
1
vote
1
answer
3k
views
SMTP: Received from unknown [xxx.xxx.xxx.xxx] -> but IP does have a valid PTR/RDNS
I got the following problem. I got an smtp-relayserver that collects outgoing mails from other servers and checks them (spam assassin).
Now the headers are showing this:
Received: from ...
- 953
-1
votes
3
answers
1k
views
What hostname and rDNS should I choose?
What should I set as hostname and rDNS?
1 server
3 domains (domain1.com, domain2.net, domain3.de)
1 mail server for each domain
My current settings:
/etc/hosts
127.0.0.1 localhost
11.22.33.44 ...
- 179
1
vote
1
answer
10k
views
No PTR record according to gmail
Recently, I installed iredmail on my VPS and configured DNS records (including ptr). It confirms nslookup:
nslookup zelenin.top
Name: zelenin.top
Address: 191.101.251.182
nslookup -query=mx ...
- 13
1
vote
1
answer
1k
views
"Bad PTR DNS Resource Record" when sending E-Mail from Shared Hosting
I have a virtual server with one IP x and have multiple sites a.com and b.com running on it.
When accessing x in the browser, I get to homepage a.com.
Sending an e-mail from a.com to GMX is without ...
- 111
1
vote
1
answer
3k
views
hMailServer and reverse DNS
I have an hMailServer installation on a Windows 2012 server VM and need to properly set up reverse DNS + the mail server in order to avoid getting e-mails bounced back from certain big providers, ...
- 133
7
votes
1
answer
13k
views
Reverse DNS is not a valid Hostname error from MXToolBox
I can't send email messages from my server. However, I can receive email messages. I set up my server the exact same way I did many times which I've proven it works and it's pretty straightforward and ...
- 171
0
votes
0
answers
112
views
Mailserver complains about reverse DNS lookup on my Gateway
I am presented a mail server setup, that is working well. There's only a small issue, which makes me think, there's something wrong in the DNS setup. It is a small setup with a Debian mail server (...
- 143
0
votes
1
answer
513
views
rDNS and forward DNS for mail server behind firewall, different IPs
All,
Here is my setup :
Firewall(x.x.x.114) <--> mail.mailserver.com (FQDN) (x.x.x.118)
When sending mail, header has following IP ...."Receivedfrom mail.mailserver.com ([x.x.x.114])", my ...
- 65
5
votes
1
answer
26k
views
Reverse DNS does not contain the hostname error from MXToolBox
I am not sure where I have gone wrong in my configuration but I am getting the error Reverse DNS does not contain the hostname for my domain sparkdojo.com I had the hosting company set the PTR record ...
- 53
2
votes
0
answers
2k
views
Postfix on server with multiple IP addresses sends mails with wrong HELO in header
I have a VPS with multiple IP addresses:
venet0:0 x.x.x.2
venet0:1 x.x.x.3
venet0:2 x.x.x.4
venet0:3 x.x.x.5
All IPs have A records
m2.domain.com -> x.x.x.2
m3.domain.com -> x.x.x.3
m4.domain.com ->...
0
votes
1
answer
85
views
What should be the reverse DNS for the email server?
When I nslookup x.x.x.x my web server's IP address I get this error: Non-existent domain.
Must it return the top domain like mydomain.com or it is okay to return some.random.subdaomains.mydomain.com?...
- 288
2
votes
2
answers
9k
views
mx server: multiple domains on one ip
I'm just a bit confused about the correct DNS setup for hosting multiple domains on a single server with one ip.
For example the mail server (domain/reverse: example.com) should host 3 domains:
...
- 165
0
votes
3
answers
1k
views
Appropriate PTR records for mail server [duplicate]
I realize this is a common question around here, but I'm having trouble understanding one part of it. I want to setup a mail server to send newsletters and other marketing emails for a few of my ...
- 507
1
vote
1
answer
880
views
hMailServer IP got blocked, what should I do?
I'm using hMailServer application in order to host my own mail server. I'm currently hosting three domains (I just buy the domain and host them in my machines)
Everything is doing well, all my ...
- 13
0
votes
1
answer
2k
views
How to get reverse DNS to work for multiple IPs and domains on Windows Server EC2 instance?
I have a EC2 instance setup running hMailServer. I have a primary IP on the system that I am using for example1.com email. I would like to also add a second domain example2.com using a different IP ...
- 982
2
votes
1
answer
574
views
The correct PTR record in DNS
I'm confused with my DNS records. I own a domain (e.g. example.com).I've set A record for my SMTP server (e.g. smtp.example.com) for outgoing emails. The email address is (e.g. [email protected])....
0
votes
1
answer
134
views
What domain to set in rDNS
I have a few different domains on a shared IP address. One of them is having trouble sending email, as certain mail servers reject the email for not having rDNS set up properly.
The thing is there ...
- 131
1
vote
2
answers
17k
views
Postfix: bouncing mail (reverse DNS issue)
I have a problem with Postfix. I get this with some email address:
to=<[email protected]>, relay=mail.domain.tld[IP_ADDRESS]:25, delay=3, delays=0/0/2.5/0.52, dsn=5.7.1, status=bounced (host mail....
- 1,807
3
votes
1
answer
10k
views
How to set up reverse DNS on Ubuntu 12.04 VPS
As far as I can remember when setting up my VPS and mail server on it, I had configured the mail server correctly. However, a few of my clients get SMTP errors,
host mx1.zonnet.nl[62.58.50.9] said: ...
- 229
0
votes
1
answer
239
views
Reverse dns and SaaS Spam Filters
We have an exchange server in the office that for a year or so has just used the built-in spam filters - we have added the SpamHaus IP addresses so that some basic spam filtering is done. However, ...
- 101
0
votes
1
answer
99
views
Mailserver DNS and rDNS setting
Let me start with the fact that things are quite weird in our organization.
Now, we have to place a mailserver for a DNS zone that is under our control, for example xxx.yyy.zzz. However, we can't ...
- 101
2
votes
2
answers
791
views
How Reverse DNS does what it does
Hopefully this is not a stupid question, but I cannot find a clear cut answer. Can someone please inform me exactly what 'source address' is used in Reverse DNS? Does rDNS pull the IP address from ...
- 185
2
votes
2
answers
4k
views
What is the correct mail set up for multiple domains on one server?
I have a machine (centos 5) with one external ip address. On that machine I have many virtual hosts with a few different top level domain names and sub-domains under those eg.
sub1.domain1.com
sub2....
- 31
0
votes
1
answer
679
views
want to Request our ISp to do rdns/ ptr modify for my Staic IP ot point to my Domain?
we setup a mail server in our local office using Mdaemon Mail Server . We have a Staic ip 123.xxx.123.xxx ( as an example ) and all necessary ports (80 , 25 , 110 ) are made open .
We have a ...
- 121
5
votes
2
answers
1k
views
Postfix & client IP reverse DNS
I explicitly added reject_unknown_client_hostname and several other reject rules to slow down SPAM in our server. So far that's working nicely.
However, there is an important client that keeps ...
- 53
0
votes
2
answers
3k
views
Email rejected for no rDNS by AOL despite having rDNS [duplicate]
I am having trouble while attempting to send a single email to an aol.com user. I get a rejection reply as follows:
Your message did not reach some or all of the intended recipients.
Sent: Wed, ...
- 291
1
vote
2
answers
300
views
Is it ok that reverse DNS for my mail server resolves to www2.domain.com and not domain.com?
I am trying to make sure my mail server is set up correctly. One of the steps is to ensure that reverse DNS works. We email from [email protected]. When I test rDNS using nslookup i get:
$ nslookup yast....
- 235
19
votes
2
answers
28k
views
PTR record (rDNS) for multiple domains on a shared IP address
I host multiple domains on a single IP address:
cats.com
A @ --> 10.20.30.40
A mail --> 10.20.30.40
MX @ --> mail
dogs.com
A @ --> 10.20.30.40
A mail --> 10.20.30.40
MX @ --> ...
- 417
0
votes
1
answer
682
views
Does RDNS for mail server have to match the mail server hostname exactly?
Typically when setting up a mail server, I create an rDNS record for the mail server IP to match the mail server hostname (ex: mail.example.com).
Can I instead set the rDNS ptr to match the parent ...
- 1,215
3
votes
1
answer
4k
views
DNS Server Configuration problem , PTR records
I have a server that using Windows server 2003 , and Microsoft DNS Server.
I have a problem on my DNS setting
ERROR: No reverse DNS (PTR) entries. The problem MX records are:
225.208.20.***.in-addr....
- 400