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
53 views

Use CNAME for SMTP Server

I am working on a project that involves use of a transactional email service (like sendgrid). My question is can we create a CNAME in our domain DNS (i.e. smtp.example.com or client1.example.com) that ...
0
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0answers
20 views

Courier authdaemon socket missing (exim4)

On my Ubuntu 14.04 server, I'm running Exim4 together with Courier. I tried to configure Exim to use a DNSBL blacklist shortly. Since I rebooted the server, the mail server doesn't work anymore. When ...
0
votes
1answer
34 views

Configuring postfix to work with TLS (mediawiki)

I have a couple of questions regarding postfix config. First of all I need TLS as of the pear smtp plugin mediawiki uses, forces TLS authentication. Will it work on 25? Or what's the advised port? ...
0
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1answer
110 views

PHPMailer with SSL - CentOS 6.7 VPS - SMTP ERROR: Failed to connect to server: (0)

I have a CentOS 6.7 VPS and PHPMailer 5.2.14 will not connect to my mail server. I have tried troubleshooting the problem but nothing has solved my issue yet. My PHP is version 5.6.18. The only output ...
0
votes
1answer
67 views

Sonicwall: cannot send email (outlook) and drops connection (google drive)

I will start by saying Im a web developer and my networking knowledge is very limited, please be patient =) . We dont have network/sysad in our company. We are having problem with our connection. We ...
-1
votes
1answer
21 views

Postfix no longer reciving mail

I installed and configured a mail server with postfix(3.1.0-1)+dovecot(2.2.21) on archlinux(4.4.3-1) in December, and on which in confirmed it to be working, both receiving and sending. About a week ...
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0answers
22 views

Cache status code of rejected relayed mail to immediately block aggressive clients?

A legitimate client relays mail over mail server A to the destination server B. B rejects mail to recipient with status code 554 and the reason "Unknown recipient". Can this rejection be "cached" for ...
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0answers
5 views

Postfix DSN suppress DSN in relaying host

I have following scenario with Delivery Status Notification smtp-client === host1(postfix) === host2 == .. === host_N I would like the smtp-client to receive DSN from host1 (sucess,delay,fail) but ...
0
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1answer
55 views

Can't open port

I can't open port 25 and 587. Background information: I am running CentOS 7 with firewalld and httpd. Now I want to run a mailserver. I started with installing postfix. Then I added firewall rules for ...
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0answers
148 views

Using PHPMailer on Hostgator (timeout when try to login into SMTP server)

solved: The problem was that to use the service through hostgator, for some reason the user must log in using main dsn name and not the SMTP domain name. I was using the simple PHP mail() function to ...
0
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0answers
43 views

/SharePoint/IIS/SMTP - emails are stuck in mailroot/Queue

I'm trying to configure SharePoint outgoing email to send e-mails via SMTP within the IIS pickup directory. Emails are just going into the mailroot/queue folder and stay there. They never actually get ...
0
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0answers
35 views

SMTP eMail to one specific client failing

We have one client with 3 domains and we send regular emails to all 3 of them. Email to these domains were sent succesfully without hitch for a number of year and only recently are failing with ...
0
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2answers
56 views

I can send email from outside but not using phpmailer (error 111)

I can send email via my webserver from my computer (using Thunderbird), but not from my website using 'phpmailer'. Oddly enough, when I run 'telnet mail.myserver.com 25' on the server, it says ...
3
votes
2answers
77 views

Postfix sender address rejected / using multiple addresses

I have an email server running Postfix that generally works great. I'm trying to use this server as the SMTP server for outgoing mail in a CRM/Marketing platform installation. I've entered the ...
0
votes
1answer
16 views

Avaya switch - need to block port 25

Situation: In QA-DEV Lab environment I need to block port 25 for the egress traffic on AVAYA ERS5510-48T switch. Question: How do I do it using EDM aka Web Interface? Couldn't find anything in ...
0
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2answers
182 views

Postfix as SMTP server for Gmail. (“Send mail as” google option)

I have a vps on ovh.com runing debian 7. I want to set up my gmail account to send, and recieve mail on (for example) myname@mydomain.com address. I searched google for hours and couldn't find a ...
1
vote
2answers
167 views

Why does my server hostname appear in Exim email headers sent from a different domain?

I've had several problems with SMTP emails from my server and domain sent using Exim being blocked by certain other domains, which may have been partly due to certain server settings tripping up ...
0
votes
1answer
65 views

What can I do if an SPF hasn't propagated weeks or months after being changed? How to force SPF to propagate?

I set up a domain, SMTP mailserver etc on a Centos box a few months ago, including PTR records that looked like this: pop PTR XX.XX.XX.XX. www PTR XX.XX.XX.XX. mail PTR XX.XX.XX.XX. Everything ...
0
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1answer
88 views

How to have exim on server with multiple domains send each mail from its own domain, not the server hostname?

Suppose I have a VPS with multiple dedicated IP addresses and multiple domains: domain-a.com is on 11.11.11.11, mx is mail.domain-a.com domain-b.com is on 22.22.22.22, mx is mail.domain-b.com ...
-2
votes
1answer
102 views

Explanation of various smtp error codes bounced by mailservers

I'd like to ask real mailserver administrators from here about some smtp error codes - I take care of some customer's mailing systems, and there is a wide range of server replies, many of them not ...
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2answers
52 views

smtp email forwards with Gmail and Wordpress

I'm looking for help. I'm trying to add a new email account to Gmail. I've done it before for one of my websites email domain and it worked fine. However, now, this is the message I get. Furthermore, ...
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1answer
37 views

MX Record for a physical server

I've a physical server which is used as a Mail Transfer Agent(MTA), I'm using postfix as SMTP server and cyrus as IMAP. I've a static IP for the server and have SSH access to it. Postfix and cyrus ...
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0answers
50 views

Postfix with Dovecot Disconnects after STARTTLS on Port 25

I am having a lot of trouble setting up the Postfix to do STARTTLS. It seems that I could successfully send outgoing mail using Thunderbird. However, I can't seem to get the Postman SMTP for Wordpress ...
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0answers
31 views

Mail subdomain not connecting to Windows Server Virtual SMTP via Telnet Client

I trying to set up subdomain (e.g mail.mydomain.com) for use with a virtual SMTP server running on windows server 2012 SP2. I’ve tried to telnet with the command ‘telnet mail.mydomain.com 25’ but it ...
0
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1answer
35 views

Exchange 2013, flow messages to a third-party smtp

I plan to use a SMTP Archiving feature in my archiving solution (non Microsoft). I wish to send a BCC copy of every message to a particular SMTP server (installed on archiving software). In Exchange ...
0
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1answer
69 views

mutt failed to send mail with error "sendmail: Cannot open mail:25

Hi I am trying to send mail using mutt command as below, mutt -s "test" madk@mycompany.com </dev/null This fails with following error, sendmail: Cannot open mail:25 Error sending message, child ...
2
votes
1answer
51 views

Exchange Online, Mandrill, SPF and DKIM

I have a customer ABC Ltd (abc.ie) who has a requirement to send emails via SMTP to their own customer base from within an application that we have developed for them. For their company email they ...
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0answers
146 views

Postfix couldn't send mail on Ubuntu VPS server, network unreachable/connection timeout

I have a problem with postfix. When I am trying to send some mail from commandline, I get: Feb 14 12:44:35 some-server postfix/smtp[1022]: connect to ...
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votes
2answers
71 views

What's the usual re-sending time period for SMTP servers? [closed]

What I want to ask is about SMTP servers, say, which operate at different IT companies (hosting SMTP servers, corporate SMTP servers etc.) I know that every server can be configured differently, but ...
0
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0answers
14 views

Which host(s) to include in SPF record to prevent email spoofing [duplicate]

I've got domain name and email hosting from a third-party hosting provider (1and1). Some of the email addresses under the domain are being spoofed by spammers. In order to mitigate this I'd like to ...
2
votes
1answer
34 views

IBM Domino - incoming e-mail loses formatting, no winmail.dat

IBM Domino 9.0.1FP4 HF523, IBM Notes 9.0.1FP5 We have a problem receiving incoming SMTP e-mails from a particular (external) sender that's only recently started, in that all formatting is stripped ...
0
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0answers
37 views

mail server should anyone be able to send internal mails from external IP without authentication?

Sorry for the long title. My parent organisation that owns the company I work for accepts emails to be sent from test@org.com to test@org.com when connecting via port 25 telnet externally. I'm ...
0
votes
1answer
39 views

Mail reaches SMTP Server but isn't delivered to Exchange?

I recently setup my own Exchange and SMTP Server on a virtual memberserver. Now if I send a mail (with my .net script) it reaches and passes the SMTP Server but it doesn't show up in my Outlook inbox. ...
1
vote
1answer
53 views

Best way to combine Google for Work with postfix mail server / e-mail routing

I am re-designing our company mail services, and we are migrating some mail-boxes to Google for Work. The objective is to have some users in the cloud, and some users on an on-premise Postfix server. ...
0
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1answer
45 views

Exchange - non-received mail return code 5.7.0 Access denied

I am experiencing strange problems on our Exchange servers (exchange 2003 SP2); lately some domains can't communicate with our server. We are able to send messages outside without any problems, but ...
0
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0answers
22 views

535 error from gsmtp

I am using Erlang and its esmtp library to send emails from my application. It used to work OK and still works fine on the development machine. Unfortunately several weeks ago it stopped working on ...
1
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1answer
29 views

Postfix canonical map for forwarding

Because of problems of IP/domain reputation (my server and domain very recent), I had to use Amazon SES as SMTP relay to be able to not have my mails flagged as spam. My setup with Amazon was working ...
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0answers
12 views

SMTP IIS getting 452 status

I'm receiving emails on a Win 2008 R2 server via SMTP. Some of the emails are rejected with status 452, while others are accepted. I've disabled all size limits, including drop disk quota, but the ...
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0answers
21 views

Postfix intercept emails with apache server

I have a server(using postfix) to relay emails to a smtp server. I am tasked with separating the emails by the domain(2 to be exact) to send to 2 separate smtp servers. The idea was to use transport ...
0
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2answers
227 views

SMTP server ready but 'Could not connect' error appears

I have set up a web server to use an SMTP server to send out emails. Here is a section of the log entries generated when I try to send a test email: 2016-02-03 10:20:01 CLIENT -> SERVER: STARTTLS ...
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0answers
14 views

Postfix smtp send (from Email + ip ) condition if not reject . how to?

Dear friends, i have case that require that i should allow some application to send without authentication (done mynetworks). my problem if i allowed any ip to send using mynetworks it can send from ...
1
vote
1answer
66 views

How to move the Inetpub\mailroot folder on SMTP Windows Server 2003 where Exchange isn't installed

Can anybody enlighten me on how to move the C:\Inetpub\mailroot\ directory to a different location i.e. D:\ on a Windows 2003 Server that does not have Exchange installed on it? The only modifiable ...
3
votes
1answer
88 views

Do any versions of Microsoft Exchange Server support RFC 5336 / 6531(Internationalized mailbox names)?

https://en.wikipedia.org/wiki/Extended_SMTP#SMTPUTF8 The SMTPUTF8 extension allows UTF-8 encoding in mailbox names and header fields. This provides the capability for sending email to ...
1
vote
2answers
65 views

Why does DMARC operate on the From-address, and not the envelope sender (Return-Path)?

Several emails sent from my webserver to a Gmail address, where the From: address is websitevisitor@gmail.com, have been marked as spam by Gmail. The From: field is populated from form data, and ...
1
vote
1answer
40 views

Purpose of SMTP message routing (relaying)

I am wondering why SMTP is designed in a way which allows intermediate MTA on the path of a message. According to RFC 5321, The objective of the Simple Mail Transfer Protocol (SMTP) is to transfer ...
0
votes
1answer
28 views

Added second Exchange 2010 server, getting delivery delayed to external users

We have on Exchange 2010 server in our domain, on-premises. We added a second Exchange 2010 server in our cloud environment, which is also part of our domain and connected with a site-to-site VPN ...
0
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0answers
29 views

Configuring IIS 7 SMTP settings via powershell

I need to touch up the list of IP addresses that can relay through my SMTP virtual server in IIS. I've been trying to get a handle on what cmdlets and to use in my script but am struggling a bit. ...
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0answers
27 views

IIS 6.0 SMTP not sending NDR to user from web application

We have a web application that is configured to use an internal mail relay running on Windows Server 2012 R2, IIS 6.0 for the SMTP though. I just put this server in place as a replacement for an old ...
0
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0answers
26 views

How do I configure the listener binding address for python 2.7 smtplib running in a windows environment?

I am setting up an application called openemm which uses the python 2.7 smtplib to handle smtp transactions. My outgoing mail works fine but smtplib is not responding to incoming requests on port 25 ...
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1answer
93 views

Is it possible to use CDO libraries (classic ASP) to send mail to Office 365 / Exchange Online?

I'm working on a migration to Office 365 / Exchange Online for a SMB company which until now has been running a local Exchange 2010 server; we're talking about ~25 mailboxes here. However, there's a ...