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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Sending emails from non-configured domains with postfix/dovecot

I am trying to setup a mail server with postfix/dovecot. I can currently receive emails and send emails from domains that I have configured. I have a lot of domains and my email setup is simple - ...
1
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1answer
84 views

Postfix lookup failure: works from localhost, not on other nodes in LAN

I am getting temporary lookup failure for the recipient address when trying to send email using Postfix and Gmail from a machine other than the host, on the same network. It works just fine when ...
0
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2answers
51 views

How to set exim to use outside SMTP?

I want my scripts on the server to be able to send emails, but via outside, 3rd party mail service for which I'm paying anyway. I have exim and even dovecot installed anyway, but I suppose i will need ...
0
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2answers
43 views

Disable SMTP on Windows SBS 2011

I have a server running Windows Small Business Server 2011 Standard. I have disabled the SMTP service, removed the Web Server Role, and blocked port 25 in Windows Firewall. Why am I still able to ...
0
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1answer
68 views

Incorrect FQDN on Exim4 send-only SMTP mail server

I am pretty new to Linux systems and I am trying to send e-mail to my gmail ID using exim4. I found many tutorials for exim4 online and I am doing exactly that, however I never receive any email. The ...
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0answers
54 views

google apps mail error

In recent months, we have big problems when we send email on our own mailing list (for safety, I'll call our domain name example.com ^^ ) staff@toto.com. All users receive this kind of mail back from ...
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1answer
110 views

gmail blocking postfix relay [closed]

Here is partial postfix config: relayhost = [smtp.gmail.com]:587 smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous ...
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1answer
70 views

Sendmail (or postfix or somebody) not speaking SMTP

I've got a Linode Debian server which tries to send email (normally through PHP, but mail from the command line doesn't work either). But the mail never arrives successfully. My two clues from people ...
0
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2answers
49 views

Which Exchange 2013 Role will allow mail relay

We have a service that connects to our default receive connector in exchange, which relays the message to external users. Currently I have configured the service to use my DA account which assigned ...
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votes
2answers
45 views

Exchange server accepts email without authentication. Is this a misconfiguration?

I am a user on a network with an exchange server and there is an HP scanner/email machine that can send emails with scanned docs as an attachment from any email address without authentication so I ...
0
votes
3answers
183 views

Certificate on port 25 when trying to secure SMTP with POSTFIX

Background I think I am close to getting my POSTFIX setup to my liking. I've run some SMTP online checks and my SMTP passes all the basic security tests. I get a certificate warning in Thunderbird. ...
0
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1answer
22 views

Exchange 2013 SMTP reply error not being sent

We are scanning to our exchange 2013 server from a scanning application that uses smtp, in the past when the mail exceeded the smtp size limit it would send an email with a link instead of the scanned ...
0
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1answer
41 views

Postfix with external SMTP

I'm trying to install Request Tracker and configure it to use an external SMTP server to sent mail notifications. I've already put postfix to send emails using this tutorial, but it keeps sending then ...
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2answers
27 views

Make exim accept mails to be redirected only when they can be sent

I run a small mail server with all the usual functionality: Sending of local mail, receiving mail for local folders, redirecting mail according to alias and a mailing lists. The redirections go to ...
1
vote
2answers
59 views

Incoming mail rejected with “Invalid HELO name” [closed]

I'm unable to receive important emails from someone, with this error in my exim log: 2015-01-21 11:30:16 H=xxx.xxx.xx.xxx [xxx.xxx.xx.xxx]:50143 X=TLSv1:AES256-SHA:256 rejected MAIL ...
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0answers
62 views

The Remote Certificate is Invalid According to the Validation Procedure [closed]

Seeing this error on all but ONE machine in the building. One PC is accepting the certificate and all clients are denying it. Any reason this wouldn't be domain wide?
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1answer
68 views

Postfix: delivering “local” mail to GMail, but sending other mail

I need to set up a server to send messages to a few different people automatically. The recipients are at two different domains, let's say mydomain.com and otherdomain.com. The messages need to come ...
2
votes
1answer
69 views

IIS SMTP TLS encryption issue

I enabled TLS in IIS SMTP Virtual Server with a self-signed server certificate. Made sure that the certificate has the FQDN of the server. Checked the TLS encryption checkbox in Virtual SMTP > ...
0
votes
1answer
104 views

Postfix not sending authentication when relaying to local smtp server

I have been trying to get my postfix server to relay all of my message to a local SMTP server. As far as I can tell I have everything set up right, but I get a 550 Authentication error. My local SMTP ...
0
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1answer
213 views

Postfix - SMTP mail delivery failed with “Connection timed out” error

I have installed postfix mail server in Ubuntu machine. I am facing some issues with the mail sending to other domain mail servers (Google, Yahoo, Outlook...). I am using virtual domain to send the ...
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votes
1answer
50 views

How does zimbra procedes with sending email to the same domain if zimbra is configured to relay the messages to a proxy server

Does zimbra relay emails that are from the same domain as the expeditor or the emails are send directly to the zimbra mailbox without going trougth the relay server? I have a mail p1@example.com and ...
0
votes
1answer
561 views

Windows Server 2012 R2 IIS SMTP Server Will Not Send Emails

I have an existing SMTP server on our network that is used to send emails from a variety of printers, applications, etc... I have installed the IIS SMTP Server on a new Windows Server 2012 R2 server ...
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votes
2answers
42 views

Is it possible to use Gmail for transaction email?

We currently use Gmail for our support email. For transactional email (reset password, etc) we just use default Linux Postfix server on our Amazon Web Serivce EC2 instance. My question is would it ...
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0answers
53 views

SMTP delay when sending mail from Centos

I am encountering long delays when trying to send mail with swiftmailer using 1and1's SMTP server. there is a 19 second delay everytime as shown below by tcpdump: 21:54:50.784747 IP (tos 0x0, ttl 64, ...
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1answer
109 views

hotmail.com - Unrouteable address

I'm using Exim on my mail server, and trying send email to someuser@hotmail.com address. I got email from this address, and make "replay" then. But - I have return from my SMTP with Mail delivery ...
0
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1answer
63 views

Catch all emails and pipe them all to a script with postfix

I realize this question was asked and answer before. Here's what I have done. Created a catchall address and user. Here is my /etc/postfix/virtual file. @example.com catchall Added it to main.cf. ...
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1answer
47 views

Reliable/robust method of ripping attachments from a POP/IMAP/Exchange mailbox

I'm looking for some fresh ideas after a bit of a google and would love your opinion: I have an email address hosted in exchange that will receive attachments on a regular basis. I would like a ...
2
votes
2answers
54 views

The benefit of different SIP and SMTP domains?

I was wondering if there was an advantage of having a different Lync SIP domain name from the Exchange SMTP domain name? I could see the disadvantages, but I'm trying to understand the real world ...
0
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1answer
52 views

Postfix check hosted sender domain [closed]

On my server I have this problem: there are mails sent from, example, johndoe@domain.com even if domain.com isn't hosted on my server. And, obviously, there is no johndoe@domain.com among the e-mail ...
2
votes
1answer
244 views

cannot find postfix/mailx email in maildir, why not?

In a CentOS 7 development machine, I have configured postfix to allow emails to be traded between localhost addresses. Mailx is also installed. I am able to send email, and the log files indicate ...
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2answers
104 views

Postfix & Amavis - Use UNIX Soket for Communication

I currently using a complex mailserver setup using Postfix, Dovecot, Amavis and Spamassassin. Everything works fine but I want to improve the Postfix-Amavis-Communication. At the moment, postfix will ...
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votes
1answer
56 views

Secure cloud to internal Mail setup using UUCP or something more modern

Some of our Linux servers are going to be moved out into a cloud. But the servers need to be able to email our users internally and are required to use our domain name as sender. The server cannot ...
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0answers
64 views

Local Xeams standalone server not sending emails?

I want to setup a Ruby On Rails development environment where I can develop an application that can send emails. I can use the smtp.gmail.com free server but I do not want to use it, but rather I want ...
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2answers
66 views

should multiple servers each run a full postfix stack, or use one central mail server

I have a collection of servers that will each have their own tasks. web server, billing server, game servers. Each of which will need to either send customer facing email, or simply send it's system ...
1
vote
1answer
20 views

Add an alias in postfixadmin with smtp access

I want to create a second identity support@mydomain which I want to send emails from. My mailbox is info@mydomain, so receiving emails should still go into this same info@mydomain mailbox. In my ...
3
votes
1answer
73 views

Relay email for some addresses, forward for others with Postfix

I administer a domain (let's say example.com) for a client who uses an Exchange server at an external service provider for email. So I made the MX record point to the Exchange server, let's say ...
5
votes
1answer
851 views

Roundcube & Postfix SMTP: SSL routines:SSL3_READ_BYTES:tlsv1 alert unknown ca:s3_pkt.c

I have a Postfix / Dovecot / Roundcube setup that I use personally, as well as provide to other users. I am attempting to transfer this entire setup to a new box, but having some issues. Mail ...
1
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1answer
76 views

Are “via” and “on behalf of” headers determined by both DKIM and SPF?

To get rid of the "via" and "on behalf of" headers in Gmail and Outlook, do I need to set both the DKIM and the SPF records, or are DKIM records enough? We recently changed our SMTP provider from ...
0
votes
2answers
384 views

postfix fails to send mail with “fatal: unknown service: smtp/tcp”

I have installed postfix, and when I tried to send a mail to gmail it told me that it has been sent, but when I checked my inbox in Gmail I didn't saw it. This is how the connection looked like: $ ...
1
vote
1answer
47 views

using a self-signed certificate with Amazon SES

I'm configuring Amazon Simple Email Service, I get to the point when I try to send an email and I get the error message: The SMTP server requires a secure connection or the client was not ...
1
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1answer
923 views

450 4.7.1 Client host rejected: cannot find your hostname

I have a Postfix/Dovecot email server which fails to deliver emails to some addresses. Here's an example of what is says: <xxxxx@board.com.ua>: host mail.da.net.ua[91.213.154.4] said: 450 4.7.1 ...
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vote
1answer
149 views

Postfix DSN code explanation

Since few days ago I was unable to receive automatic emals sent from my PHP application. When I use Terminal to send an email to my @gmail address, everything works. When I try to send it to my ...
5
votes
1answer
47 views

Is Exchange 2010 compliant with RFC 3848

I have looked up Exchange 2010 Support for RFC Standards but do not see RFC 3848 amongst the supported standards. I do see RFC 4954 listed, which 'recommends use of RFC 3848 transmission types', ...
1
vote
1answer
139 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 ...
3
votes
1answer
167 views

Postfix SMTP relay server

I use gmail to receive e-mails both from my gmail address and my own domain, but gmail no longer allows you to send e-mails from your own domain name unless you provide your own SMTP server to send ...
4
votes
1answer
184 views

Postfix SMTP authenticated can send as anyone

The server correctly accepts/rejects the logins though dovecot's authentication mechanism, but after that I can pretend to be anyone when sending emails. smtpd_sender_login_maps = ...
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0answers
199 views

PHP mail() function - “from” name overwritten by Exchange Server

I originally posted this on stack overflow but was told it might be better placed here on Serverfault. I am trying to send a very simple email from a php script ...
2
votes
0answers
108 views

Does Google require TLS on port 587? Exchange 2010 SMTP has mail sent to GMAIL backed up in queue

Exchange 2010 SMTP has mail backed up in queue. Any email sent to Gmail sits in the queue while any email sent to another personal domain which has email filtering enabled errors, "asp.reflexion.net ...
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1answer
79 views

Limiting OpenVZ SMTP Per Hour

How would I limit SMTP connections per hour on the host node for a /24 block? For example, I want to limit it to 50 emails per hour. Thanks
0
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1answer
118 views

Postfix forward incoming emails to mailin

I've setup the smtp server using postfix with dovecot on mail.example.com server running on port 25. And then I've also setup another smtp server using mailin (http://mailin.io) on mail.example.com ...