SMTP is the Simple Mail Transfer Protocol, the most recent standard of which is defined in RFC 5321. It's the Internet standard for sending and receiving email.

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Steps to take to improve email deliverability [duplicate]

Successfully delivering email to my clients is a pretty high priority at my company. We are of course fully opt-in, paid clients, no possibility of spam, the whole thing. The information we email is ...
8
votes
5answers
100k views

Reverse DNS - how to correctly configure for SMTP delivery

I started a new service and we need to send emails to our customers (new account confirms, etc). My server is known as prod01.bidrodeo.com and resolves to 97.107.134.38 . For reverse DNS, ...
1
vote
1answer
653 views

SMTP 25 closed even I allow everything in firewall, debian server running sendmail

I am running sendmail + dovecot in my debian server. I have enabled the firewall rules to allow everything iptables -P INPUT ACCEPT iptables -P OUTPUT ACCEPT iptables -P FORWARD ACCEPT ...
4
votes
5answers
25k views

mail loops back to myself | postfix

Hi I have an issue with bounced mail it does not happen all the time but at the same time is very frequent. Most of the time if I send an email to an address that does not exist then i get a bounce ...
22
votes
5answers
177k views

How to correct Postfix' 'Relay Access Denied'?

This morning, in order to correct a problem with a name mismatch in the security certificate, I followed the recommended steps from How to fix mail server SSL?, but now, when attempting to send an ...
1
vote
1answer
143 views

postfix discard or change Message-ID header based on another header line

I want to change the Message-ID header or better yet, discard it. I know everyone is going to ask "Why would you want to do that?" because I know it sounds weird to even write it. Well I am ...
0
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6answers
552 views

ISP blocking port 25

My ISP has started blocking port 25 so I can not send email through my dedicated server any more. I have several options: Send email through the SMTP server provided by my ISP. Any problems with ...
16
votes
6answers
14k views

How to Setup Ubuntu Mail Server with Google Apps?

I have a domain, let's call it foobar.com. All of the MX records for foobar.com point to Google's mail servers because I am using Google Apps for your domain to manage it. It's great because everyone ...
8
votes
4answers
12k views

How does a Reverse DNS lookup work with regards to spam filters?

I have heard that most spam filters use a reverse DNS lookup on the originating IP address of the sending SMTP server (or something like that) as part of the verification process. I want to make sure ...
7
votes
7answers
26k views

How to configure php.ini with remote SMTP?

How do I configure PHP to send mail using mail() via a remote SMTP server? I've tried to do this using php.ini but it seems that you can only do that under Windows32 and I want to do this on my Unix ...
13
votes
5answers
10k views

Do SPF Records For Primary Domain apply to subdomains?

I have a quick question regarding SPF records: Do they need to be present for all subdomains? Lets say that I have a TXT record with SPF info for domain.com Let's also say that I have a seperate ...
10
votes
4answers
12k views

When exim4 sends HELO/EHLO, how do I configure which host name it sends?

Mails from my system are being rejected when the receiving server does HELO checking. I believe my system is sending the wrong domain name. I'm running exim4. Googling for anything about exim4 and ...
8
votes
5answers
6k views

How important are PTR records for Email Servers?

Does anyone know of any studies done to show how much email will be rejected if there is not ptr record for the SMTP banner name of an email server? Are reverse checks always done when enabled, or ...
5
votes
5answers
4k views

Many ISP's is block port 25, how do I choose an alternative port?

I am building an application that will be acting as a combined MUA/MTA on different networks. However, many of the networks are with ISP's that block port 25 for SMTP. Therefore I would also like to ...
2
votes
2answers
3k views

Postfix: send all bounce messages to postmaster

The situation is that we have a number of guests, say 80, sending through a central mail infrastructure out to the web. The way the network is setup the mail server cannot necessarily initiate ...
1
vote
1answer
248 views

Postfix - sender dependent configuration based on client IP instead of email address

Using Postfix, I want to setup the transport according to the sender IP. There is sender_dependent_default_transport_maps, which does it according to the sender email address (envelope MAIL FROM). ...
17
votes
1answer
29k views

What ports to open for mail server?

I have just finished setting up a Postfix mail server on a linux (ubuntu) platform. I have it sending and receiving email and it is not an open relay. It also supports secure smtp and imap. Now this ...
13
votes
2answers
10k views

Correct use of SMTP “Sender” header?

Our web application sends email messages to people when someone posts new content. Both sender and recipient have opted into receiving email messages from our application. When preparing such a ...
11
votes
4answers
1k views

Has anyone ever used SMTP site links?

A simple real-life question, inspired by a comment here: Active Directory has supported inter-site replication using SMTP instead of direct RPC since its first introduction in Windows 2000. But did ...
7
votes
3answers
59k views

554 - Sending MTA’s poor reputation

I am running an email server on 77.245.64.44 and have recently started to have problems with remote delivery of emails sent using this server. Only about 5% of recipients are rejecting the emails, but ...
3
votes
4answers
5k views

SMTP relay through GMail overrides “from:” address with “[me]@gmail.com”

I've been trying to figure out if this is a new "feature" or if there is an issue with my configuration. I'm using Ubuntu 10.04 Desktop with Postfix as MTA. My smtp (as opposed to smtpd) ...
0
votes
2answers
3k views

SMTP server for centOS, other than Postfix?

I need to install smtp server on centOS, but I don't want to use postfix. please suggest some others smtp servers and how install using putty.
8
votes
4answers
5k views

What host name should the SSL certificate for an SMTP server contain?

I have a server foo.example.com at 192.0.2.1 It runs exim to receive e-mail for several of my domains. My domains each have an MX record pointing to mx.example.com, which resolves to 192.0.2.1 If I ...
2
votes
4answers
4k views

Exchange 2003 - how to route ALL mail (including internal) via an external SMTP gateway? (Or, domain/mail server migration for the masses.)

Short version: Is there a way to have Exchange route all email, including internal AD users that would normally be routed directly, through an external gateway? (SMTP, probably a "Smart Host" in ...
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vote
1answer
160 views

Postfix unknown command

I'm running two milters on my current postfix installation. I'm noticing that, from one particular client, they are sending an invalid command consisting of the first 3 letters of their domain name. ...
1
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6answers
4k views

E-mail sent with postfix are marked as spam

I am using gmail as my email provider for a domain name that I control. I want to send email from my dedicated server that is being hosted by a real hosting company and I don't like the 500 message ...
1
vote
1answer
108 views

Dedicated Server emails ending up in Junk

I have a dedicated server that works fine. Recently I added a new domain with a new dedicated IP address. The emails from the webserver gets sent out from the primary IP address which is different ...
0
votes
1answer
1k views

How can we support all domains in postfix smtp server?

I have installed and configured postfix on our server. Postfix config file has relay_domain parameter which contains the list of domain names which postfix will support. Is there a way by which we ...
8
votes
4answers
10k views

What are SMTP relays and smarthosts?

What exactly is an SMTP relay, and what exactly is an SMTP smarthost? Can someone give me a brief description of each, including how they relate to one another?
7
votes
5answers
4k views

Is the IIS SMTP Server good enough for a production server?

I was planning to use the SMTP server that comes with IIS7 (for a website) but then I came across this link and started to get worried (read the accepted solution), on the other hand I have a limited ...
3
votes
0answers
4k views

nginx as smtp proxy [closed]

I was ordered to configure nginx as SMTP proxy. That's all details I have. I've looked though some books and docs and don't see neither any examples of such configuration nor explanations of why this ...
3
votes
4answers
304 views

Minimize the chance my email is blocked/filtered as spam

I'm running a web-based store where order confirmations are sometimes blocked and don't reach the intended user. The structure of the business model is such that our product is marketed to the ...
1
vote
1answer
3k views

Exim mail server slow on sending through SMTP

It takes about 30 seconds for the server to send me the banner, but initial connection is done instantly only happens when I am at the office, from home it works fine at the office I have a rRns ...
1
vote
3answers
397 views

Recommended SMTP Relay Service [closed]

I've got a legacy application that needs an smtp server to relay emails. Each client has various control over their IT infrastructures (from little to none at all), so I can't necessarily install an ...
1
vote
1answer
107 views

Ubuntu: mailserver + database

I want a mailserver on Ubuntu that saves e-mail in the database and uses users in the database to let them login into the POP server and SMTP server. There are also different domains. How can I do ...
1
vote
3answers
1k views

SMTP host name vs. domain in “From:” address vis-a-vis Email Deliverability

I'm trying to implement (or make sure that I'm correctly following) email sending best practices to improve deliverability, but the role of the smtp server's host name vs the domain name of the From: ...
1
vote
2answers
2k views

Recommended MTA for Windows Server

I need an mail server running on my web server that will just route email through other email servers. Exchange requires Active Directories which just complicates an otherwise simple setup. What are ...
1
vote
2answers
834 views

IIS SMTP server (Installed on local server) in parallel to Google Apps

I am currently using free version of Google Apps for hosting my email.It works great for my official mails my email on Google is support@mydomain.com. In addition I'm sending out high volume mails ...
0
votes
1answer
265 views

SMTP traffic timing out on my server [closed]

My mail server is not getting or processing incoming e-mails. I recently changed my MX record to point to a different router on my network. I opened port 25 on the router and pointed it to my mail ...
0
votes
1answer
191 views

Enabling per-virtualhost email relaying through external user/pass smtp relay [duplicate]

Possible Duplicate: Postfix configuration: different outgoing hosts based on sender I've got a problem that's driving me mad. Basically, I run 10 virtualhosts in a CentOS distribution. ...
0
votes
2answers
1k views

What does it mean to setup Postfix as “SMTP only”?

I am trying to setup Postfix a few different domains on a virtual host. I need to have email setup just to send out registration confirmations and new password requests. No one will have a mailbox on ...
0
votes
3answers
2k views

SMTP server for Linux with simple configuration

I'm looking to replace our aging mail server and I've decided that I want to change the SMTP server software we use. We currently run exim. Over the years I've worked with a number of other MTAs ...
-3
votes
1answer
76 views

How to configure exchange 2010 to be used as an external smtp relay? [closed]

I'm currently trying to configure our exchange 2010 to be used as a external smtp relay. What I'm trying to do is allow certain websites that we manage to send email using our exchange server smtp ...
-3
votes
2answers
401 views

Postfix SMTP server issue

So I have an Ubuntu Linux box machine for my website. (not ran locally at home, it is a public linux box). But for some strange reason I can only send Email from my home machine to this box in ...
6
votes
1answer
24k views

How to configure sendmail to send email via GMail (smtp.gmail.com), using port 465 or 587?

I have configures sendmail to send email via my GMail (Google Mail) account, i.e. via smtp.gmail.com, by editing /etc/mail/sendmail.mc and regenerating sendmail.cf: -dnl ...
37
votes
4answers
4k views

Is greylisting still an efficient method for preventing spam?

I've used greylisting on my servers for many years, but I don't know how effective it is nowadays. Is it still good for fighting spam in 2012? Or is the typical spammer MTA capable of resending ...
17
votes
3answers
19k views

What replaces IIS SMTP server in Windows Server 2012

I have read the notes here http://technet.microsoft.com/en-us/library/hh831568.aspx regarding deprecated and removed features in Windows 2012 and it says that SMTP is deprecated. I assume this is ...
9
votes
8answers
31k views

Send an email with an attached file using telnet or netcat

I often use telnet or netcat to connect smtp servers to send an email as a test. Does anyone know how you would send an email using telnet or netcat but attach a file as well? There are probably ...
8
votes
1answer
5k views

How can I configure Postfix to ignore relayhost for some domains?

Is there a way in Postfix to ignore the relayhost? I have something like relayhost = [smtp.domain.net]:587 Now for a certain domain I don't want to send it out to that relay but want it to just ...
5
votes
5answers
33k views

How do I configure reverse DNS for a SMTP server [duplicate]

We use iis 6 to send out emails for our website but some email addresses bouce backs. It only appears to be 2 addresses. There is at least 100 different email addresses sent to at the same time as ...