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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1answer
31 views

Automated blacklist checker [on hold]

Has anyone used any of these services and if so, is there one you can recommend? Ideal target would be for an MSP so perhaps would like real time alerts if an IP shows up on blacklist for perhaps ...
0
votes
1answer
29 views

Postfix Splitting Domain to Separate Mailstores using LDAP

I'm investigating a new mail setup to replace Exchange in our organization using Cyrus-IMAP, Postfix and Perdition IMAP proxy server. I'm running into issues dealing with sending emails to different ...
11
votes
2answers
281 views

Is it still “wrong” to require STARTTLS on incoming SMTP messages

According to the STARTTLS Spec Section 5: A publicly-referenced SMTP server MUST NOT require use of the STARTTLS extension in order to deliver mail locally. This rule prevents the STARTTLS ...
-1
votes
1answer
30 views

MX Records and smtp server [closed]

i've got a question. If i've got my webserver that have a domain, for example mywebsite.net, and i want to send an mail with PHP using a remote SMTP server which have it's own host, for example ...
-1
votes
2answers
85 views

GMail detecting mail as spam [duplicate]

I've been trying for a long time to get our company's mail server send mail that will get accepted by the GMail spam filter. I have managed making it work for Yahoo Mail and Hotmail, sadly GMail is ...
-1
votes
0answers
10 views

Inbox lock for exclusive access [duplicate]

-I found server logged into mailbox on my smtp server -This server released connection for inactivity after 10 minutes. -in the 10 minutes between logged in & disconnected for inactivity, 3 ...
0
votes
2answers
42 views

Dovecot pop3: Disconnected for inactivity

We've application fetching messages from mailbox inbox. Once, application stoppped fetching, then we'd the following in maillog: Aug 15 11:03:47 server_name postfix/virtual[16743]: 731E258003: ...
1
vote
2answers
17 views

Set default gateway based on protocol using pfSense

I have a pfSense configured with two Internet links for broadband load balancing. One of these links block outgoing traffic on 25 port (WAN1). I have a mail server (IP 10.6.9.2) that should use the ...
1
vote
1answer
39 views

Unable to lock error message in SMTP Server

I've the following error message appeared 3 continuous for the same mailbox > (delivery failed to mailbox > /var/spool/postfix/vhosts/<user>/mail/inbox: > > unable to lock for ...
1
vote
1answer
59 views

What happens inbetween SMTP and POP3?

I understand SMTP, and to a lesser degree POP3, but I feel like I'm missing a large chunk inbetween. I see this image on a Microsoft page: and I feel like what I'm missing is the "Internet" part. ...
1
vote
1answer
30 views

“4.7.0 Timeout waiting for client input” error Exchange 2013

I am having trouble sending mail from several servers with the following error when trying from command line. -> (telnet 25, mail to rcpt to data etc.) 250 2.1.5 Recipient OK data 354 Start mail ...
0
votes
2answers
27 views

Open Postfix or Sendmail to all IP's

Can I configure Postfix or Sendmail to allow all IP's without authentication? I understand that this could lead to all sorts of abuse. We have some monitoring systems that send notifications out via ...
0
votes
2answers
37 views

Which domain should have 'abuse' or 'postmaster' or “fbl” email accounts?

Consider that I am providing SMTP services for several clients and the sender / SMTP domain is mails.mysmtp.com. When client A is using my email infrastructure, he may use from address (from header) ...
0
votes
0answers
43 views

Exchange 2013 Client Frontend connector will not accept TLS

I have a new Exchange 2013 environment running on Windows 2013 R2 with 2x Edge and 4x CAS/Mailbox servers deployed. It is deployed in a resource forest, with proper trust relationships established to ...
0
votes
1answer
68 views

Using SMTP Relay on a Exim Server in VPS for Multiple Domains

I am moving my email behind a dynamic IP, and I will need to SMTP relay outbound email in order to avoid spam lists. My domain is hosted through a BlueHost VPS running EXIM. I am wondering what I ...
0
votes
3answers
59 views

Windows Server SMTP Feature - Installation Ramifications

Background: I am a SQL Server DBA. I have inherited about 50 SQL Servers and need to set up various maintenance plans and alerts. To get the full benefit, I'll also need to configure Database Mail ...
0
votes
1answer
62 views

Setting up ubuntu to send mail from PHPMailer

I have a small server, inside the company where I work, which has an app that needs to send email to notify users for different reasons. I'm using PHPMailer to do this. But as I suspected, I need to ...
-2
votes
1answer
35 views

Limit Emails Per Hour Per IP [closed]

Anyone knows a script or software for CentOS and Windows that can be installed onto dedicated servers with no control panel limiting emails per hour per IP or full block. Thanks in advanced!
0
votes
1answer
25 views

Exim4 require TLS for all hosts but localhost

As my webmailer does not support STARTTLS and I want to enable relaying for everyone at localhost, I would like to have Exim advertise AUTH PLAIN and LOGIN only without TLS if the connection was ...
-1
votes
1answer
64 views

Postfix sends as hostname.domain.com instead of domain.com

I've been trying to set up a debian mail server running postfix, but when I try to send mail via mail example@outlook.com the recipient sees the sender as hostname.domain.com. The hostname it sends ...
-1
votes
1answer
37 views

Postfix cannot send to external domains

I set up my Postfix with a sasl link to a Dovecot user / domain database. Postfix is giving the following error message when trying to send mail to external recipients (internal are fine): Server ...
-5
votes
1answer
105 views

How to setup SMTP server to allow mailing to any recipient? [closed]

I have a windows server, acting as a web server and mail server. For the mailserver I use hmailserver and works fine recieving emails but not so good sending emails because I cannot setup reverse DNS ...
0
votes
1answer
48 views

Is there a way to send email using port 465 only? [closed]

I'm trying to send email via port 465 since my ISP has blocked the port 25. openssl s_client -crlf -connect example.com:465 EHLO example.com AUTH LOGIN sdgfsdgfdgdfg dfgdfgdf mail from: ...
0
votes
1answer
52 views

Postfix virtual mailbox base, uid, gid — good user and group choice?

I often see tutorials for setting up Postfix with the virtual mailbox delivery agent on Linux that instruct to create a new disabled-login user and group to own virtual mailboxes in ...
0
votes
1answer
35 views

Trac notifications (smtp) and Postfix

I've two separate ubuntu 12.04 servers. Runs Trac (homeserver/Dyndns) Runs postfix (VPS/staticIP) I configured trac to use TLS and connect to postfix server. Trac config: admit_domains = ...
-1
votes
1answer
32 views

At what point should I dedicate a server for SMTP [closed]

I currently have a 2GB RAM windows server 2012 which is has IIS and SMTP installed on there. Now I seen alot of people leave SMTP out on the webserver and buy a server just dedicated to handle the ...
0
votes
1answer
70 views

Postfix still complains that “certificate verification failed” even when “smtp_tls_security_level = fingerprint”

I'm attempting to use Postfix (version 2.6.6 on RHEL6) to connect to and send mail via a mail relay on our internal network. I want to connect with STARTTLS on port 25 (port 465 is not available on ...
1
vote
1answer
29 views

Swiftmail cannot use sendmail/postfix

When I try to run some Kohana swiftmailer I get the following error in maillog: Jul 23 17:18:37 ads postfix/sendmail[5818]: fatal: execv /usr/libexec/postfix/smtpd: Permission denied The output of ...
0
votes
0answers
48 views

determine which application is sending mail via postfix

I would like to track down which applications (other than PHP, which I can track via mail.log setting in php.ini) are connecting to and sending email via postfix. Is this possible via any log ...
0
votes
1answer
63 views

exim4 - Why is rate limiting outbound mail to a smarthost only working with acl_not_smtp?

In an effort to rate limit outgoing emails per recipient (all emails are sent by the same user), I've been doing some testing in a very simple environment: ...
0
votes
0answers
50 views

syslog-ng 3.5 flush_lines not working with smtp

What I want: automatic emails every time someone successfully logs into my Ubuntu 14.04 LTS server. /var/log/auth.log gets 2 lines written to it every time I login. Example: Jul 22 13:55:49 server ...
0
votes
1answer
21 views

monitoring availability of publicly accessible distribution lists

I have an unusual request from management: to set up monitoring of public-facing email addresses that resolve to distribution lists(groups). We are using Exchange 2010 to host these lists/groups. I ...
-1
votes
1answer
69 views

How to setup intermediate SMTP mail server / relay to filter outgoing emails

I want to block all outgoing emails except to few whitelisted domains. what are the best ways to go about it? Can I put an intermediate Intranet server which will do filtering based on whitelist and ...
1
vote
1answer
70 views

Postfix 5.7.1 Unable to relay [deliver internal mail directly]

I have the following scenario: serverA = RHEL5 using Sendmail serverB = RHEL6 using Postfix serverC = RHEL6 using Postfix gwsmtp = relayhost example.com = domain name As we are migrating from ...
0
votes
0answers
39 views

Server sometimes doesn't receives e-mail, with error 451

One of my customers tried to send me an e-mail with his e-mail address that I didn't received. He received a Delivery Status Notification (Delay). I only received the message 2 days later In the ...
0
votes
2answers
45 views

Mail delivery to not-yet-migrated accounts in O365 staged migration

I'm about 10% through a staged migration from Exchange 2003 on-prem to Office 365's Exchange Online. The question I have is how do the migrated users that are now successfully using Exchange Online ...
0
votes
0answers
45 views

hotmail isn't receiving mail from my server

Hotmail is block all mails (not send to Junk, it really block!) send from my VPS server (even if I send directly from roundcube, for instance). I checked all configs and seems that all is ok. Works to ...
0
votes
0answers
89 views

Postfix: Relay Access Denied, Reverse DNS Mismatch Error

I have dovecot and postfix installed to handle emails. I have used telnet to check imap and it appears to work fine but when i run telnet mail.domain.com smtp i get 554 5.7.1 <user@gmail.com>: ...
0
votes
1answer
27 views

Postfix relaying to local instead of relayhost

I am trying a simple postfix relay of emails via an SMTP server. But I see from the logs that the mails are relayed to local and not to the relay host. The main.cf configurations are below, ...
1
vote
1answer
49 views

Postfix Outgoing Mail Suddenly Being Deferred

I am having trouble sending mail with postfix after changing the "Format for usernames that include domain" under the "Mail For Domain" template. Basically I had everything working but then changed ...
1
vote
1answer
22 views

Does IIS 6 Virtual SMTP Server support UTF/Unicode Subject Lines

I have a Windows 2008 R2 server running IIS 7.5 hosting a bunch of websites. These websites relay email through the IIS 6 Manager's Virtual SMTP Server. I'm trying to verify whether or not this ...
-1
votes
1answer
107 views

My server does not listen to port 25, even though iptables allows smtp traffic [closed]

My public server accepts traffic and relays them to other machines on the network with iptables PREROUTING rules. I recently added a mail server at 192.168.1.10 and made its iptables rules to accept ...
1
vote
2answers
56 views

Simplest Way to Setup Email for Various Domains

I'm beginning to use Mandrill to send out transactional emails from my various domains. Now what I'd like is a way to receive these emails simply w/out setting up a mail server on my linux boxes. I'm ...
1
vote
2answers
63 views

Postfix Domain Whitelisting in Combination with Sender Authentication

I'd like to whitelist several domains in my Postfix configuration in such a way that all e-mails from those domains are accepted as long as they're properly authenticated using SPF and/or DKIM, should ...
0
votes
1answer
53 views

SMTP retry interval - Lotus Domino

Our ISP only accepts 5 emails per transmission. If I do a manual send (route *), then I usually get the error: 57 Retry( 2) SMTP [$Retry MY_ISP.COM] (Push) Last error: 421 4.4.2 Message submission ...
0
votes
2answers
138 views

SMTP don't work when try to send mail from mail clinet

Mail server works fine when send mail from server, but when I use some mail client it not work. I found this in logs: Jul 12 19:45:04 tvsite postfix/smtpd[3356]: warning: hostname adsl-bb29-l44 does ...
0
votes
1answer
76 views

EXIM - 550 Cannot receive from specified address - Sendgrid

We're having some intermediate issues with exim where some emails go through and then others get the 550 Cannot receive from specified address Error. This is the guide we used to setup EXIM: ...
0
votes
2answers
46 views

Remote IP and SMTP Proxy

Is it possible to proxy emails - with postfix for example - transparently so the backend mail server will get the last SMTP server IP address (rbl purpose) and not the Proxy IP address? If it is ...
4
votes
3answers
89 views

Will mailing lists “break” if SPF is too restrictive?

I have recently configured my own mail server (Linux-based postfix + dovecot scenario). This is just for personal use - I have no bulk mail going out, no automatically generated mail outbound from the ...
0
votes
2answers
52 views

View realtime list of connections to Postfix

I am running Postfix on a linux box with a couple hundred local users with mailboxes. Is there a way to monitor all incoming connections (SMTP) to the Postfix service? I.e. a live stream of "IP ...