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Questions tagged [email-server]

Refers to the hardware or software that make up a server dedicated to sending and receiving emails. Many popular modern email servers bundle other functionality for contacts and calendaring along email delivery.

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Email Proxy or Email Relay? Which is Best? Which Server Should Store SSL Certificates, Mail Relay or Mail Proxy? [on hold]

I am new to ServerFault and this is my first question and I am posting this here as I was unable to find adequate information on internet. I want to setup a Postfix Email Server on Debain environment ...
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1answer
68 views

multiple MX pointing to the same server

I need help for a mail server configuration. I would like to know if it's possible to have multiple MX with different pub IP, pointing to the same local server. this is because in my environment exist ...
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24 views

Sendmail redirect copy of all incoming mails to another server

I am migrating a mailserver running sendmail 8.14.3 to a postfix server. The MDA on the new server is Dovecot. In order to ensure a seamless transition, it would be best if incoming mails are ...
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0answers
12 views

The server does not support the IMAP4 IDLE command

I have a console based application which is running on the server 24X7 to keep checking any incoming emails and perform action on the basis of email information received. It was working fine on ...
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0answers
7 views

Postfix myhostname attribute and rDNS

I run a mailserver on Ubuntu using Postfix to serve a domain I have. Let's call it domain.com. For this domain, I have the follow DNS records: A domain.com 1.2.3.4 A mail.domain.com 1.2.3.4 MX ...
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23 views

Supporting multiple domains under one mailserver

I'm running my own Ubuntu server using Postfix to serve my email needs for a certain domain (let's call it domain.com). The mailserver does not have a mailbox, it forwards received emails to assigned ...
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0answers
25 views

Email server security [closed]

I am writing an email server from scratch. (For learning and also eventually replace my gmail). I have no plans to send via this server (only for receiving email). My goal is to not miss any non spam ...
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2answers
26 views

Why my postfix server is connecting to outside IP constantly?

I've set up a VPS which is working fine. I'm using postfix server to send email using PHP. I was just checking the log files and I noticed that my server is getting a connecting request or connecting ...
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22 views

G Suite - dynamic outbound e-mail address based on recipient domain [on hold]

My company is using G Suite for e-mail and we need to alter the outbound sender e-mail address dynamically based on the recipient e-mail address domain. We use two different domains for our business; ...
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0answers
30 views

My postfix server rejects my python script - “Client host rejected: cannot find your hostname”

I have a postfix on a server. When I'm trying to send an email from my python script, it gets rejected due to "Client host rejected: cannot find your hostname". How to allow an email come through? If ...
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2answers
47 views

POSTFIX cant connect from SMTP with TLS

Thanks all for helping me :),i was working a direct bulk mail sender project, my program was running properly then it gave me an error then i've spend too much time with a lot of searching from ...
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1answer
23 views

Correct DNS Settings for iRedMail (or other mail servers)

Given a fresh install of Ubuntu with a FQDN of example.com $ hostname -f example.com If user installs iRedMail (or another mail server) using demo.example.com as their first mail domain name. His ...
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2answers
24 views

How does yum-cron send emails from localhost?

I have an amazon linux 2 server running in the aws cloud and I have yum-cron running on it. I have an email domain mydomain.com which is running on a separate server in a completely different cloud ...
1
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1answer
77 views

Postfix changing email address to 1@hostname.example.com

I followed this guide one to set up email using postfix, dovecot, and mysql using vhosts. When I send an email to the mailserver it gets bounced back and I get the following message in /var/log/mail....
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1answer
71 views

How to change UID,GID of user accounts while migrating from one server to another Centos 7 server

I have a mail server running with 1000 users. I want to migrate the server to Centos 7 server. Scenario 1 (Old server): user accounts UID start with 501 Scenario 2 (New Centos 7 Server) : user ...
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0answers
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Removing Microsoft Safelinks Trackers in Postfix

I'm receiving mail forwarded from MS/Office365 mail. Microsoft, bless their inquisitive soul (and I'm using bless in the broadest meaning possible), think it's a splendid idea to track all clicks on ...
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2answers
59 views

Prevent using spam trap e-mail address on registration

I am running a website where the users register using their e-mail addresses and receive a confirmation code before they can log in. (After this every contact is opt-in.) Every now and then some user ...
1
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1answer
25 views

How outbound SMTP gets encrypted by the client?

When my SMTP server sends an email to another server and is supposed to use TLS, the receiver will offer his destination domain certificate (I assume). Which certificate does my server use to encrypt ...
2
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1answer
31 views

Utilize AWS SES as an Inbound Mail Gateway

I am trying to use SES to intercept an incoming email for a domain, do some processing and manipulation of the email with a lambda, then would like to continue sending the email to the final ...
4
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1answer
50 views

Sender Score Low

We host our own email server and have discovered we have a low sending score that is causing delivery issues. From the report (senderscore.org), there is an IP address outside of the U.S. (email ...
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1answer
59 views

Postfix error while sending through MS Office 365

I have configured the Ms office 365 in postfix. But am facing the error while sending an email. Here is the log. AD0C147573: lost connection with smtp.office365.com[40.97.188.242] while sending RCPT ...
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0answers
24 views

Bounce all emails with tracking pixels: G Suite mail server

I'm trying to bounce every email that has a tracking pixel in it. Can it be done with a G Suite server for all people on our domain? Ideally it'd also send a message explaining our company does not ...
2
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2answers
237 views

Postfix email server not receiving email from external email

I'm trying to set up a mail server on Ubuntu 16.04.5 LTS with Postfix and Dovecot. I can send out email without any problem and mail sent from localhost also finds its way into the inbox. However, ...
2
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1answer
28 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 ...
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1answer
131 views

Postfix: How to limit outgoing messages (smtp) while sender_dependent_default_transport_maps is enabled?

I would appreciate and thankful if anybody could suggest me regarding the following issue I am dealing with for the last 7 days. Current Condition: 1 working mail server (collocation) that host for ...
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1answer
33 views

Putting an e-mail domain to blacklist

Is it possible for us to put a specific e-mail domain to blacklist? I know you can personally tag and report as spam/scam e-mail for the incoming ones (to a specific email address, more like ...
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2answers
102 views

What availability is needed for an E-Mail server to not lose messages?

Setting up an E-Mail server, I wonder, what if it goes down. Do I need a redundant setup in order to not lose incoming mails? Or would it suffice to make sure it doesn't go offline for longer than, ...
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2answers
67 views

Is a mail subdomain necessary?

I have just taken ownership of a domain which had a couple of associated email addresses. I have left the mail boxes with the previous host, and so have been looking at updating the MX records in my ...
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1answer
27 views

How do I fix messages frozen by exim due to a typo in recipient?

I have a couple of frozen messages in my exim queue which have a misspelled recipient, e.g. reciepint@domain.tld instead of recipient@domain.tld. Apparently they could be fixed by correcting the ...
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1answer
47 views

Poste.io - can't login by mail application - bad SSL certificate

I have a proble with poste.io and configuration with nginx-proxy. DOMAIN is valid domain :) This is my docker-compose for poste.io: version: '3' volumes: mailserver_posteio: services: ...
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1answer
36 views

sender_dependant_default_transport_maps not being used by postfix

Intent We are trying to use the sender_dependent_default_transport_maps feature of postfix to use different SMTP relays based on the from address of a mail. The goals are: allow our partners to use ...
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1answer
32 views

Postfix is appending myorigin to non-FQDNs despite “append_at_myorigin = no”

I have postfix and a local LMTP server running. In my main.cf, I have append_at_myorigin = no. When I run postconf|grep append_at_myorigin I get that this value is no. But for some reason, postfix is ...
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0answers
31 views

Using OpenDMARC's SPFSelfValidate option to perform SPF check

OpenDMARC has a SPFSelfValidate option described as following in the man page: Causes the filter to perform a fallback SPF check itself when it can find no SPF results in the message header. If ...
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0answers
68 views

Backscatter relay from Postfix backup mx server causing spam (553 5.7.1)

I have 2 Postfix Servers MAIN.mail.example.com BACKUP.mail.example.com Problem scenario: If spammer sends email from "me" to me directly to BACKUP, server forwards it to MAIN MAIN server reject ...
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1answer
64 views

incoming email in postfix centos 7 server not getting inbox

I'm using Centos 7 and postfix. While I can send email from my server but I can't read email because not getting emails in my postfix "maildir" than I command to check mail logs - [root@server ~]# ...
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47 views

Connection to the IMAP server interrupted when connecting to Postfix + Dovecot from Outlook

Goodmorning everyone. It's been some time since I have a problem with the configuration of my mail server on Ubuntu Server 18.04.01 made with Postfix and Dovecot. When I try to send / receive emails ...
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0answers
15 views

Office365 removes mail headers before send

We're sending mails using c# Mail library, we need to send specific headers to track them through external providers. We've tried some months ago and it worked, but now trying again before deploying ...
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1answer
126 views

Postfix - Rspamd + amavis

Currently I have Postfix with Amavis, Spamassassin, Clamav and all the bells and whistles up and running. I would like to add RSpamd to the configuration, I don't want to replace Amavis, just keep ...
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1answer
180 views

SPF and DKIM configuration Ubuntu 18.04 fails

I have been following this tutorial from DigitalOcean. I have followed every detail but nothing seems to work as expected. Assuming that my FQDN is the following: mydomain.com. Here are my details: ...
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0answers
35 views

Do you need to use IMAP to read bounced emails?

I'm writing a send email app in Laravel which will use my own email servers. Many apps read an IMAP inbox to log the number of bounces a user might receive- using some cron to check and delete bounces ...
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0answers
56 views

Dedicated IP for low volume transactional email?

I have a website where customers pay to access online training. During the training we need to prompt the customer a handful of times via email which gives us a total of between 500 and 1000 ...
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1answer
19 views

Unknown non-local mail is being sent from Postfix?

I'm keep seeing these lines in the Postfix maillog, from serveral unknown non-local email-addresses: Oct 3 08:47:32 srv04 postfix/pickup[86325]: F020C5C1101: uid=80 from=<noreply@example.se> ...
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0answers
62 views

Is there an option for nginx mail module to use STARTTLS on upstream servers?

I'm currently setting up a mail cluster for sending mails. To avoid sending limits of various providers (like gmx) I decided to setup a smtp loadbalancer using nginx and multiple postfix servers as ...
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1answer
66 views

SMTP Server All Records OK But All Email Sent in Spam

i bought a VPS with dedicated IP address and running windows Server 2012. I installed an SMTP server and DNS server, created all needed records: SPF, DMARC, DKIM, PTR, MX, and A. These results test ...
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1answer
126 views

Error: SPF record must be in the correct format

I need some help with set up the SPF record. When I created the SPF record just like this: v=spf1 a mx include:_spf.google.com include:getresponse.com ~all When I run this for a test: https://...
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1answer
44 views

How to let Postfix relay mails at least once

Setup: Internet <> Firewall Firewall <> DMZ (192.168.200.0/24) Firewall <> Green (192.168.100.0/24) 192.168.200.11: Proxmox-Mail-Gateway 192.168.200.12: Postfix I have set up a Mail-Server-...
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0answers
49 views

zmconfigd service failed after trying to do Relay per domain

I was trying to do mail relay per domain in Zimbra mail server using this documentation After I done the changes mentioned "ZCS 8.8 instructions" section and try to restart the services of zimbra ...
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1answer
69 views

Is it Okay for an MX Record to Differ from Incoming/Outgoing Mail Server Address?

I'm sure this is a beginner question, but I could use some help. I run a VPS and am familiarizing myself with DNS settings and my mailing set up. I began when one email address consistently ended up ...
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2answers
173 views

“My domain” is being recognized as spammer for “no reason” [closed]

I linked my brand new domain, to yandex.connectand I sent only a few test emails, but NO email was sent or received. I checked many times the DNSs and they seem to be fine, When I send emails from ...
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3answers
50 views

Internet email is being routed to origin (@) IP address instead of address specified in MX and A record

We have setup a mail server and created the following DNS records. Assuming our domain is example.com: A @ 10.0.0.5 A mail 10.0.0.1 MX example.com mail.example.com ...