All Questions
24
questions
0
votes
0
answers
111
views
Postfix delivers messages locally despite configuration for discovering external agent
A small node operates several web applications attached to a domain.
The same domain is used for mailboxes, hosted off site by a commercial service.
On the name server operated by the registrar, A, ...
- 330
0
votes
1
answer
317
views
Change mail from header in sendmail
We have two separate RTs (request trackers) configured on one server. They both are configured to send the emails through sendmail. We are trying to configure now SPF and DMARC records for these DNS ...
1
vote
1
answer
1k
views
Which domain is HELO checked against with rDNS? Mail server's domain, even if different from the sender's domain? Or the email sender's domain?
I run a small webserver that hosts a handful of domains which I use for personal and testing purposes. I want to set it up as a mail server as well, and I'm trying to understand the rDNS lookup that ...
0
votes
0
answers
52
views
Do there exist open-source tools to process and aggregate DMARC and MTA-STS reports?
Both DMARC and MTA-STS provide email addresses for 3rd parties to send delivery reports in XML or JSON formats.
Are there any FOSS tools that process and aggregate these reports? There are 3rd party ...
- 495
2
votes
1
answer
37
views
Is there a DNS-based policy like SPF or DMARC to require STARTTLS sessions for a given domain?
Ignoring the fact that not all mail servers support TLS:
Is there a way to announce to the world that we would prefer that our inbound mail be delivered via TLS and verified as signed by a trusted CA?
...
- 495
2
votes
3
answers
379
views
Malformed hostname in an MX record, possible?
I'm wondering if it's possible to publish (and receive) a malformed hostname (e.g. a hostname starting with a digit or with a hyphen, etc.) in MX lookups? Does the DNS server usually validate MX ...
- 214
-2
votes
1
answer
189
views
Impossible to create an email address from the postfix admin
Good morning,
I am doing a year-end project which consists in creating a postfix mail server, I arrived at the creation of emails except that when I want to create an impossble mail addendum I have ...
1
vote
1
answer
209
views
What's required to let a domain send outbound emails from multiple domains?
Let's say I have:
40 outbound emails to send
main domain - main_domain.com
4 separate domains-workers with Postfix - mail.my_postfix1.com...mail.my_postfix4.com
Goal: send 10 emails via each of 4 ...
- 29
0
votes
1
answer
858
views
Can't get DKIM Key
I am having an issue with not finding the public key of DKIM. I am using a local DNS (BIND), so there isn’t a problem with propagating. I just copypasted the output of given generated public key into ...
- 21
1
vote
1
answer
315
views
Postfix Null Client Settings
I would like to set up a Postfix null client, i.e. a mail server that sends but does not receive emails, on an Ubuntu 20.04 machine. I spent days trying suggestions from tutorials, the Postfix ...
- 71
1
vote
1
answer
951
views
How to configure an email-forwarding system, usable as "MX" record in DNS
Context: let's say I have the domain example.com, but the registrar doesn't provide an "email forward" system.
How can I configure postfix (or even a simple Python script would be better, ...
- 2,549
0
votes
1
answer
2k
views
How to Create a PTR Record for AWS Mailserver's Elastic IP Address
I configured an SMTP server (Postfix) on an AWS instance. However, as a defense against spam most well-managed emailservers will reject messages sent from any host whose IP does not resolve back to ...
- 2,574
-2
votes
1
answer
211
views
I am not able to receive emails on my VPS [closed]
I am using linux (Debian 8) on my VPS server. I use virtualmin to handle all domains. I created emails using 'create new user' in the 'edit users' section. I can send emails to others, but I am not ...
- 7
-2
votes
1
answer
504
views
Domain doesn't exist message
I'm Trying to send mail from my RedHat 5.9 machine. so a command look like this:
echo "Test mail" | mail -s "test" [email protected]
will end up me getting an error mail look like this:
> ...
- 3
0
votes
2
answers
720
views
Receiving email on a fresh new Debian
I re-installed a fresh clean Debian 8 on my VPS.
All is set up to default values.
dpkg -s exim4 and dpkg -s postfix says that exim is not installed, and that postfix is installed. This is confirmed ...
- 2,549