Tagged Questions

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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3
votes
1answer
233 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 ...
0
votes
1answer
7 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
37 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 ...
1
vote
1answer
28 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 ...
1
vote
2answers
20 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
15 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 ...
2
votes
1answer
44 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
26 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
votes
1answer
14 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 ...
-2
votes
0answers
60 views

Why does postfix give “lost connection after EHLO” error when Gmail tries to connect to my SMTP server? [closed]

I'm trying to setup my gmail account so that I can send emails that appear to come from another email address I own (myuser@mydomain.com). Instructions to do so are here. When I try to do it, it ...
0
votes
1answer
51 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 ...
0
votes
2answers
33 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
34 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
0answers
15 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
0answers
10 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 ...
0
votes
1answer
126 views

postfix RCPT TO Temporary lookup failure 451 && mail transport unavailable

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 ...
0
votes
3answers
63 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
51 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
0answers
22 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
171 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
77 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 ...
0
votes
0answers
14 views

Monitor outbound SMTP Xen node

Using Xen-PV on one of our nodes, looking for some suggestions on how I can monitor anyone sending mass outbound emails. May be using Tcpdump?
0
votes
1answer
47 views

Postfix SMTP authentication [duplicate]

I used this guide to create a mailserver for a small business: https://workaround.org/ispmail/wheezy. IMAP is working perfectly but i ran into an issue with SMTP and Authenticated SMTP. When i use an ...
-1
votes
0answers
14 views

Postfix+dovecot+pgsql: Relay access denied [duplicate]

I just set up my first mail server and have one problem with sending email through it. I created an account in thunderbird and I'm able to receive mails sent to my mail-server but I cant send any ...
0
votes
1answer
89 views

Postfix wont send mail to external email addresses listed in virtual_alias_domains

We have our main server at mail.mainserver.com with the catchall address catch@mail.mainserver.com We also have two other domains: domain1.com and domain2.com which are hosted at gmail. Gmail is ...
0
votes
1answer
21 views

Reliably identify sender in Exchange SmtpReceiveAgent

I use Exchange as a simple SMTP server and I want to take specific actions depending on who the sender is. I made a connector which allow basic authentication (auth login) and a SmtpReceicveAgent. I ...
-1
votes
0answers
76 views

Unable to Stop Mail Server Abuse [duplicate]

I have a mail server that has somehow been compromised. Its been well over a week and since then I have changed many settings to no avail. As a first step I saw the mail logs which indicated a high ...
0
votes
1answer
130 views

Postfix SMTP Server fails to send messages to anyone outside the domain

Here is the result of a recent test on my SMTP server, I just want this server to send emails which used to work perfectly upto about a week ago Resolving hostname... Connecting... SMTP -> FROM ...
-1
votes
1answer
37 views

Sendmail emails going to spam [duplicate]

I have sendmail installed on CentOS 6 and whenever I try to send an email, it goes to spam on the recipient. (Gmail in this case) OK, so, the domain I was to send mail on behalf of is: scalpello.info ...
0
votes
1answer
64 views

Postfix config for backend webservers behind a load balancer [closed]

I've two web servers (ws1.example.com, ws2.example.com) with postfix installed locally as a mail rely (using mandrillapp), user access them via www.example.com, which is a load balancer On ws1, the ...
0
votes
1answer
41 views

Sendmail's MTA, MDA and SMTP 550 User Unknown forwarded to postmaster

I have two boxes running sendmail and configured as: MTA accepting connections from the outside world (mta.xyz.com) MDA accepting connections from internal network and storing them in user mailboxes ...
0
votes
1answer
60 views

Postfix: use relayhost only when direct delivery not specified

I read up on using relayhost with Postfix 2.6.6. It's possible to use different relay hosts, with different credentials, for different senders. But how do I use direct delivery with specific senders ...
1
vote
0answers
71 views

vCenter Server Appliance email's not reaching smtp server

Email's being generated from my test alarms in vCenter are not being forwarded to the proxy / SMTP server configured. I run tail -f on the mail log file when generating a test alarm and I can see the ...
-1
votes
2answers
108 views

“Connection to host lost” on telnet to port 25 [closed]

i installed smtp4dev to test receive mails in my localserver(xampp) for the registration form here: https://github.com/panique/php-login note: localserver is on port: 8080 my php.ini file for SMTP ...
0
votes
1answer
48 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?
3
votes
1answer
129 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: ...
1
vote
2answers
202 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 ...
0
votes
1answer
402 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 ...
-1
votes
1answer
70 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 ...
-1
votes
1answer
124 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 ...
0
votes
3answers
77 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 ...
-6
votes
1answer
47 views

Automated blacklist checker [closed]

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 ...
1
vote
1answer
95 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
315 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
2answers
177 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 ...
0
votes
2answers
112 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
44 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
62 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
70 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
492 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 ...