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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155 views

How do I configure Postfix to accept SMTP for local users with “@” (at sign) in logins?

I have an Ubuntu 14.04 server at mydomain.com with a bunch of users with @domain in login, like us.er@mydomain.com. Each of them has an "pseudo" account us.er-mydomain.com with the same uid, passwd ...
0
votes
1answer
75 views

Exchange SMTP authentication issue with spammers

I have a single Exchange 2013 server with all the roles and it looks like it's being used by a botnet. It is sending mails every 10 minutes to a specific domain from a specific user. It is not an ...
0
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0answers
53 views

CentOS/sendmail = How to prevent emails from getting “defer” when sent from php mail() function? [duplicate]

I am working on a server running on CentOS (goDaddy VPS). I have WHM setup on it. And I am getting a lot of delays in emails being sent from php's mail() function. I am looking at the Email > Mail ...
1
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1answer
72 views

iPhone SMTP Server errors with Regional Cell Carrier

I run an email server (CommuniGate Pro) under Red Hat Linux for our organization of about 200 employees. Many of our employees use their phones (iPhones 5 or later), to get their email. Some use IMAP ...
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1answer
80 views

Rewrite sender when relaying to provider server [duplicate]

I am trying to relay email thru my provider that has a mail server for my domain (xxxx.com). My postfix is configured as follows: relayhost = [smtp.xxxx.com]:25 the server requires authorization, ...
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0answers
37 views

Can't connect to any SMTP server from neither of the Macs in the network

For a few days now we have been unable to send out any E-mails from various Macs in the network to various SMTP servers. No changes to any hardware or software have been done in the recent time that ...
0
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1answer
218 views

ERROR: account.INVALID_ATTR_NAME (invalid attr name: invalid attr name) - zimbra

I followed this link to configure outgoing SMTP mail for Zimbra. In the step zmprov ms <server> zimbraMtaSmtpSaslPasswordMaps lmdb:/opt/zimbra/conf/relay_password zimbra show me the error's ...
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0answers
166 views

IIS SMTP SmartHost configuration failing to send for a specific domain recipient

I have an web application sending email (pickup folder) using the local IIS6.0 SMTP server. It is configured to send email via Rackspace as a SmartHost. We have a problem sending emails to a ...
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votes
2answers
41 views

E-mail reputation using our domain as the from sent by e-mail marketer

My boss wants to send a marketing e-mail to a large group of our customers. I personally feel that it's outside of our core business and don't support it, but that's about all I can do. Normally the ...
0
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0answers
257 views

EXIM re-routing mails through Mandrill to circumvent Gmail rate-limit

I have two domain (lets assume example.com and example.net) where we have 300+ mailboxes. Users email themselves and outside the company. Most of the emails sent outside the company are to GMAIL. ...
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2answers
2k views

How do I configure PostFix to allow phpmailer to send out email through it?

I have setup postfix on CentOS and trying to configure phpmailer with smtp authentication. Phpmailer will only work if i put 0.0.0.0/0 under mynetworks in postfix main.conf mynetworks = 127.0.0.0/8, ...
4
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0answers
56 views

How can I explicitly disable TLS when sending to one specific recipient?

I have a SendMail 8.14 server deployed in the middle of an SMTP workflow (Outbound mail looks like Exchange -> SendMail -> Appliance -> Internet) I have TLS configured for the first three hosts. ...
0
votes
1answer
232 views

How to connect ubuntu to external smtp on port 587?

I have a fresh ubuntu server installation with no firewall and want to setup ssmtp to an external smtp server (e.g. smtp.mandrillapp.com:587), however, I couldn't get my server to connect to any ...
2
votes
1answer
143 views

Exchange 2010 SMTP Pipelining support not working correctly

Am trying to configure a Sophos Appliance (SEA) to handle anti-spam. Part of this service is recipient validation, which interrogates the downstream MTA, in our case, Exchange 2010, for a valid ...
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0answers
169 views

SMTP proxy (relay) with SSL

Short question I need some kind of SMTP proxy server which does not verify passwords and directly pass credentials and data to a target server. The target server uses self-signed certificate so I ...
0
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1answer
86 views

Getting unknown mail requests on my SMTP server

I set-up a private mail server on my VPS. I get a lot of mail request on the SMTP server while I did not send them by myself. I disabled the bounce mail to prevent spamming other mail addresses. How ...
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0answers
252 views

AmazonSES + DKIM + Hotmail = temperror

Although SPF is passing, I'm getting a dkim=temperror on hotmail only (it's working on Yahoo and Gmail). I'm using AmazonSES, and already have the proper CNAMES for DKIM signing on my domain at ...
2
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1answer
94 views

What's the proper way to setup a domain name to not accept email?

RFC 5321 sec. 5 states that: SMTP clients must look up for an MX record; if no MX record for domain is present, look up for an A Resource Record (RR), and if such record is present, treat it as an ...
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0answers
28 views

Windows server | HmailServe | Relay

My setup: I am using PHPMailer (smtp) to send out emails via my websites. I am using a windows 2012 server as my mail server which is using Hmailserver. I am using Mailgun to relay my emails. Things ...
0
votes
1answer
452 views

how to send email from an instance without using sendgrid? [closed]

My project up and beta running on google compute engine. I want to set-up email server. For that i followed http://www.krizna.com/centos/setup-mail-server-in-centos-6/ I edited /etc/postfix/main.cf ...
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2answers
1k views

CentOS 7 ec2 smtpd - Client host rejected: Access denied

I've been trying to figure this out for hours and can't quite wrap my head around it. I have a mail server on an ec2 instance running CentOS7 that has postfix, courier (authlib and imap), sasl, ...
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1answer
123 views

Iptables SMTP re-routing on a proxy

I'm lost... Any help would be appreciated :) I have a mailserver. Unfortunately, the provider deny the smtp 25. I don't want to use ESMTP or a vpn. So here is the project : I have a dedicated server ...
0
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1answer
56 views

How to make exim4 on Debian safe?

I am running exim4 on a vanilla Debian Stable system. The machine has proper DNS A and MX records. I want to use it as a mail server. SMTP with TLS already works fine for authenticated users. ...
1
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1answer
74 views

Does SendMail Support TLS Certificates With Subject Alternative Names?

CentOS 5.x Does SendMail support TLS certificates with Subject Alternative Names? I have a set of sendmail servers and would like to use the same certificate for all of them (to save time and ...
3
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1answer
383 views

Does closed Port 25 cause mail to be marked as spam?

I have a web server where I have installed Postfix for sending emails only. All incoming mails will be handled by google apps and not my web server. Using iptables rules, I have blocked all incoming ...
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2answers
354 views

Postfix login mismatch sender address rejected

I'm getting the following rather annoying error message: Sender address rejected: not owned by user subscription@****.ca; from=<subscription@****.ca> to=<webmaster@****.ca> proto=ESMTP ...
2
votes
1answer
355 views

Centos SMTP error command not implemented

I have a vps with Centos 6.5 and postfix installed. When I want to connect to a smtp server like google or mail gun, I get the error 502 command not implemented. Can anybody help me please? This is ...
2
votes
1answer
211 views

Postfix SMTP server gets “550 Requested mail action not taken: Invalid IP”

I have a SMTP server named smtp-ca.mdpi.com and when sending emails to some specific chinese email domains, I am getting back: 550 Requested mail action not taken: Invalid IP<64.15.147.140> (in ...
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2answers
385 views

Postfix and access restrictions for unknown clients

I'm trying to configure a postfix mailserver and I have a doubt related to parameters like smtpd_reject_unlisted_sender and that sort of things. Of course, I would like to configure my server in such ...
0
votes
1answer
28 views

sending e-mails via sendmail using virtual-users

Currently my sendmail send e-mail with following header: Received: (from www-data@localhost) I want this header to be like: Received: (from contact@mydomain) but I am also hosting multiple ...
3
votes
3answers
530 views

Postfix + Php Mail() VS Postfix + SMTP

Most CMS (Joomla for example) comes with php mail() as default and has the option of changing it to SMTP if we want. I will be setting up both the webserver and mail server (Postfix) in the same VPS ...
2
votes
0answers
159 views

Getting “5.7.1 Unable to Relay” intermittently on mails sent to Exchange 2013

I have a helpdesk system that sends mails through the local exchange server. Until a few days ago, I never had issues with it. For the last week we have started getting complaints about missing ...
0
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0answers
230 views

Use nginx as reverse proxy for outgoing mail

We have a production server running a singlepage web-app and a separate proxy server, for security reasons. Every request to our web-app is handled by our reverse proxy (nginx) on the proxy server. So ...
0
votes
1answer
30 views

Make exim4 only send mail, do not make it receieve mail

We send email locally using exim4, but we use Google Apps to receive our email. Unfortunately, exim4 is not sending mail addressed for our domain (internal notifications) to the Google Apps mail ...
0
votes
1answer
56 views

Postfix acts as sender for unathenticated connections on port 25 for $relay_domains

My postfix can be set as SMTP server on any email client, on port 25, no auth, to successfully deliver e-mail to any domain listed in $relay_domains. This is bad, and can be easily used to send spam ...
0
votes
1answer
50 views

Exchange server relay [duplicate]

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 ...
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votes
1answer
126 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 ...
0
votes
1answer
546 views

SMTP server, remove port 25 for relay communication

I have setup a SMTP server in my internal network, but I want to remove the port 25 completely since my service provider limits access to port 25. However, even using port 587 in my server to ...
1
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2answers
1k views

Rate limit exim per user basis

How can I implement "rate limit" in Exim so that every user in my exim can send specific number of emails per day. List A of Users can send 100 emails per day and the list B of users can send 500 ...
-1
votes
1answer
134 views

Secure postfix smtp from spammer

I run on Centos 5 with Parallels Plesk 12 and look for to secure my smtp server. When I watch at log, I see some strange line like that, which I supposed it's hack connexion. Has someone any idea on ...
0
votes
1answer
42 views

Postfix: Handle different sender

I have currently the following Setup: Incoming E-Mails: Customer A -> Mailserver of Customer A All other Customers -> Default Relay For Outgoing E-Mails, I set up the sender_dependent_relayhost ...
0
votes
0answers
36 views

Exchange 2013 Outlook “Send to cache”

Having some trouble with users changing AD accounts but their primary SMTP address is moved to the new account. Let me explain: User Andersson1 gets a new AD accout because he changes department and ...
0
votes
1answer
47 views

IronPort, DLP and SMTP integration

We have configured IronPort, DLP and SMTP in my organization. Now I am getting an error message: statin - : TLS handshake could not be completed". Questions: Can anyone please tell me whether ...
2
votes
1answer
370 views

sendmail foward local mail to relay host

I have read up a lot on the subject but sadly cant get it to work. I have a Centos 6.3 with sendmail installed. The box gets used as a BackupPC server and maybe a samba server later. I want to ...
0
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1answer
6k views

postfix RCPT TO Temporary lookup failure 451 && mail transport unavailable [closed]

i configure Postfix and dovecot in fedora 20 my problem is when set RCPT TO return me 451 4.3.0 <test@example.com>: Temporary lookup failure my postfix Configuration main.cf # postfix ...
2
votes
3answers
291 views

How to isolate Google Gmail SMTP server IPs directly?

I am performing some custom routing with a VPN in the mix that is requiring me to add each Google Gmail SMTP server IP to the routing table so that they pass over another gateway than the VPN's ...
0
votes
2answers
510 views

Sending Email by SMTP IIS7.5 via php site

After my company decided to change the website we switched from old ASP.NET site to new website created in Drupal(php). The site is running locally on IIS7.5 and we also have virtual SMTP server on ...
0
votes
1answer
183 views

Exchange 2010 not receiving some emails

Exchange 2010 not receiving emails from some senders. They receive the following email rejection message: Diagnostic information for administrators: Generating server: mail.domain.com.au ...
0
votes
1answer
2k views

Zimbra doesn't send mail via smtp relay anmore

our Zimbra-Server isn't working for outgoing external mail since yesterday. Friday I installed some updates (for shell shock and Kernel updates), restarted and it worked fine. But since yesterday ...
0
votes
0answers
535 views

Exchange 2013 (CU6): Can't find named Receive Connector referenced in Event ID 1018

I'm receiving the current Event ID's 1018 on an Exchange Server 2013 (CU6) CAS/Mailbox server causing all received/incoming mail, for all users to be stuck in the mail queue (mail is received from an ...