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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“Relay access denied” when sending email via php mail in zpanel [closed]

I have installed zpanel on my centos server i am using php mail function to send signup email to my clients. it was working fine on my virtualmin server but when i moved my site to zpanel server it is ...
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1answer
111 views

Client host rejected: cannot find your hostname + SMTP

I have a VPS configured with dovecot. Now for some of the mails that I send are rejected with the following error: Any Clues?
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1answer
295 views

Very high X-Spam-Threshold when sending email through iis SMTP

I am trying to send email through SMTP configured on server 2003 over IIS 6 but I am getting X-Spam-Threshold value is 95 and I guess due to this some of my customers are not getting their emails. ...
3
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1answer
331 views

Port25.com SPF test fails, gmail SPF pass

When testing my SPF record using port25.com's nifty little tool by sending an email to check-auth@verifier.port25.com I get the following FAIL result: ...
0
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2answers
757 views

How to redirect smtp port from 25 on one ip to 2525 on another external mail.domain.com? [closed]

How to redirect smtp port from 25 on one ip to port 2525 on another external mail.domain.com? Example: I have ip as xxx.xx.xx.xxx and listening port as 25 for smtp, now I want to forward or redirect ...
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2answers
39 views

Will a mail relay be blacklisted if it accepts a mail relay request then later sends NDR?

Got a question about blacklisting behaviour. Internet MX records for "mydomain.com" point to my anti-spam gateways. The anti-spam gateways then relay the email to my mail server. If someone sends an ...
2
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1answer
2k views

Delivery temporarily suspended: Host or domain name not found

I have two independent domain ad.vz and ad2.vz, there is gateway between them. There are 3 postfix servers: mailad.ad.vz - postfix server in first domain mailsh - gateway with postfix and two ...
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1answer
231 views

postfix not going to address on same domain with gmail

I am using postfix and gmail small business apps It seems to be working great for sending email to external domains, but does not work when trying to send to email with same domain So for example ...
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2answers
604 views

Emails delivered to Microsoft/Outlook successfully, but do not arrive in inbox/spam folders

Struggling with this for awhile. Have searched everywhere, read every post/thread I can find and have a thread started on Microsoft's "Answers" site, but the replies there are so slow. I am running ...
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3answers
165 views

Dovecot: deliver reply into same folder as replied-to message

UPDATE (2 sept 2014 13:01): Just to clarify, I'm interested in handling an incoming reply from someone else, so coming in via SMTP. If it is a reply to an email that is already in some mail folder, it ...
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1answer
475 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 ...
12
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2answers
398 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 ...
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2answers
423 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 ...
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2answers
347 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: ...
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2answers
114 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 ...
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1answer
133 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 ...
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1answer
97 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. ...
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1answer
2k 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 ...
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2answers
69 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 ...
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2answers
125 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) ...
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1answer
1k 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 ...
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1answer
286 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
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3answers
281 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 ...
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1answer
2k 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 ...
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1answer
64 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!
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1answer
469 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 ...
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1answer
516 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 ...
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1answer
338 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 ...
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1answer
727 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
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1answer
207 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: ...
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1answer
190 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
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1answer
327 views

How to exempt localhost from SMTP smart relay?

I've got a mail server (mail.mydomain.com) that has a relay set up as such: /etc/postfix/main.cf: # Smarthost relayhost = [smtpcorp.com]:2525 smtp_sasl_password_maps = ...
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1answer
99 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 = ...
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1answer
42 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 ...
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1answer
1k 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 ...
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1answer
178 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 ...
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1answer
1k 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: ...
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1answer
205 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 ...
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1answer
33 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 ...
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votes
1answer
369 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
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1answer
1k 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
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0answers
180 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
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2answers
556 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
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0answers
78 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
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0answers
114 views

IIS 6.0 SMTP Relay mail to other mail server through SSL port 465

May i know iis smtp relay can/can't support to mail server (Zimbra) through SSL (Port 465). i just can see the check box of TLS encryption, pls help, thanks a lot. SMTP Relay Version Internet ...
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1answer
75 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, ...
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1answer
335 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 ...
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0answers
134 views

Forwarding email through a dummy relay to avoid blacklisting

I have a mail server that allows individual users to forward mail to other providers. The server performs the usual anti-spam checks, but spam still gets through occasionally -- especially with the ...
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1answer
81 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 ...
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1answer
311 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 ...