Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Questions tagged [smtp]

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.

Filter by
Sorted by
Tagged with
-1
votes
2answers
747 views

Internal SMTP server no longer delivering to Google Mail

Our corporate email is hosted on Google Apps, along with 5 domains for various products. Internally (Behind our firewall, not exposed to the internet) we have an IIS server running Microsoft ESMTP ...
-1
votes
1answer
182 views

Secure cloud to internal Mail setup using UUCP or something more modern

Some of our Linux servers are going to be moved out into a cloud. But the servers need to be able to email our users internally and are required to use our domain name as sender. The server cannot ...
-1
votes
2answers
1k 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
1answer
72 views

Scanning server results in warning about STARTTLS [closed]

After scanning our webserver, I've got this message: The remote SMTP service, support the user of the 'STARTTLS' command to switch from a plaintext to an encrypted communications channel. As I ...
-1
votes
1answer
673 views

Spam Filters - Why does the same message fail via one smtp server but not the other?

I have a PHPMailer script sending email. If sent via postfix localhost it is marked as spam with these headers. Delivered-To: xxxx Received: by 10.58.210.166 with SMTP id mv6csp82473vec; Sun, ...
-1
votes
1answer
2k views

How to determine if a SMTP transaction is inbound or outbound?

I was wondering how to distinguish inbound from outbound SMTP transactions. Normally this would be a straightforward question, however my SMTP server has to handle a special case: Other domains ...
-1
votes
2answers
6k views

telnet localhost smtp gives warning: cannot connect to service

I'm trying to setup a mailserver but sending and receiving is not working. I can connect to a mailbox using pop3 ( trough telnet and mail client ) When do: # telnet localhost smtp the var/log/...
-1
votes
2answers
859 views

Multifunction printer scan to SSL SMTP without SSL

We often find ourselves setting up multifunction printers which include to email capability. Until recently virtually all ISPs that we encountered did not force SSL with SMTP. More recently we are ...
-1
votes
2answers
226 views

How to read this DMARC report? Why does Yahoo still reject mails from my server?

I've got hMailServer set up on my server, which bulks-mails a newsletter to an opt-in subscriber base. I have set up DKIM signing, a SPF record explicitly giving my server permission to send email on ...
-1
votes
1answer
191 views

Postfix doesn't send mails to own domain

I have a problem that my kopano / postfix on ubuntu 18.04 doesn’t send mails to my own domain. My domain is for example: example.com I try to send a mail from admin@example.com to admin2@example.com ...
-1
votes
1answer
591 views

SMTP error 554 5.7.1 and 221 2.7.0

I have a dedicated server that connects to a webhosting to send a mails using SMTP protocol, but I get 554 5.7.1 and 221 2.7.0 errors and e-mail won't send. Full SMTP log is below. This is a script ...
-1
votes
2answers
1k views

SMTP Error 451 4.1.0

I'm adressing to you guys because I'm having a problem when sending an e-mail to a specific adress, I'm getting this message : Diagnostic-Code: smtp; 451 4.1.0 Recipient unknown I looked for what ...
-1
votes
2answers
525 views

How does IMAP/POP Server fetch emails from my SMTP server?

I have a domain abc.com with MX record/SMTP server mx1.example.com. My IMAP/POP server (incoming server) is imap.example.com and pop3.example.com. How does my IMAP and POP server fetch emails from ...
-1
votes
1answer
125 views

Mail server with different IP than webserver - getting 554 error

I have a webshop running on a Digital Ocean droplet, while the email inbox for the same domain is running on a different VPS. All of the sudden some of the emails sent by the webshop are being ...
-1
votes
3answers
438 views

What hostname and rDNS should I choose?

What should I set as hostname and rDNS? 1 server 3 domains (domain1.com, domain2.net, domain3.de) 1 mail server for each domain My current settings: /etc/hosts 127.0.0.1 localhost 11.22.33.44 ...
-1
votes
1answer
2k views

Postfix - Host or domain not found

I installed postfix on my centos. this is postconf -n output: alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases command_directory = /usr/sbin config_directory = /etc/postfix ...
-1
votes
2answers
352 views

okay to allow any outgoing port for sending mail

I have a small app on my centos6.6 server i am running that allows the user to send an email on a custom port and I am allowing any port to be used. Is there any security risk for allowing this app to ...
-1
votes
3answers
5k views

How to force Postfix SMTP to use AUTH (SASL?) and reject anonymous connections? [closed]

The following snippet has been added to the main.cf file of postfix: smtpd_sasl_auth_enable = yes smtpd_sasl_security_options = noanonymous smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd ...
-1
votes
1answer
565 views

Linux 25 port routing (tunneling/forwarding)

I have: 1) Centos server 1 with postfic/dovecot mail servers IP1 45.45.45.45 (DNS: host1.com.ua) server 1 cannot make outgoing request to 25 port because Internet Service Provider block it! ...
-1
votes
2answers
2k views

How is incoming SMTP mail being delivered despite blocked port

I setup a MX mail server, everything works despite port 25 being blocked, I'm stumped as to why I am able to receive email with this setup, and what the consequences might be if I leave it this way. ...
-1
votes
1answer
20k views

501 5.5.4 Invalid Email address when sending email in Outlook.com custom domain [closed]

I am trying to send a mail from my website through smtp.live.com port 587. I verified the credentials and even tried to send the email from Gmail by adding the account there and sending through it. On ...
-1
votes
1answer
648 views

Are SMTP headers retained when an email is forwarded or replied to? [duplicate]

Let's say an email is sent from party A to B. Let's refer to the set of headers that B views as Headers 1. Party B then replies to or forwards the email to party C. Let's refer to the set of ...
-1
votes
1answer
186 views

recipient rejected in a SMTP connection from a OpenVz container [closed]

I'm facing a strange problem. I'm getting a recipient rejected on a SMTP server only from inside an OpenVZ container, while from the physical server everything works fine. Here's an example of a ...
-1
votes
1answer
380 views

SMTP , they are hacking my server spammed? [closed]

2013-04-15 18:12:55 217.119.50.209 OutboundConnectionResponse SMTPSVC1 ADSERVER - 25 - - 250-blue-ld-242.synserver.de 0 0 28 0 359 SMTP - - - - 2013-04-15 18:12:55 217.119.50.209 ...
-1
votes
1answer
43 views

Mails are not getting delivered

I am facing the below error while sending the mail to yahoo and I have configured policyd on my server. relay=none, delay=150, delays=0.32/0.01/150/0, dsn=4.4.1, status=deferred (connect to mta5.am0....
-1
votes
1answer
3k views

How to configure a mail server on Debian Squeeze?

How can I configure a mail server on Debian Squeeze with Postfix or Exim4 without the need to relay on another smtp server? And is it possible to add multiple email addresses for the same user? (...
-1
votes
1answer
356 views

Is it safe to make ssmtp SUID root?

I'm using ssmtp, and I would like to not make my /etc/ssmtp/ssmtp.conf world-readable, because it has my gateway password in cleartext. But if it is mode 600, then ssmtp run as an unprivileged user ...
-1
votes
1answer
78 views

If i subscribe one email list on another, do the messages cycle forever? [closed]

If i subscribe one email list on another, do the messages cycle forever? why not?
-1
votes
1answer
493 views

How do I view headers, and message source in Hotmail [closed]

Hotmail changed their interface, and now I can't right click on the message (in list view) and view headers. Also I can't see the page source, besides the clutter within the regular HTML markup. Can ...
-1
votes
1answer
92 views

How can i redirect smtp port 25 to port 465 [closed]

I have Exchnage server ,I can receive emails But I can not send emails out of the domain because Port 25 is block in ISP How can i redirect smtp port 25 to SMTPS port 465 ?
-1
votes
2answers
110 views

Is someone able to sniff our corporate emails?

To put the long story short: we discovered someone is able to access some of our "secret" links we do send to our clients over email. The links are highly secured with hashes, extremely difficult to ...
-1
votes
1answer
321 views

Security issues with SMTP

I am looking at SMTP and POP3 and am trying to find the security issues with both protocols, I have found that SMTP can be easily impersonated on port 25. However I am struggling to find security ...
-1
votes
1answer
87 views

new email send to Outlook.com never deliver but reply on Outlook.com email does

I dont know where i could start. There is the probleme. If someone send me an email from Outlook.com, i received the email. If i reply, he will received my email. If i write a new email and send it ...
-1
votes
2answers
553 views

How to setup rDNS on centos 7 [closed]

Hello everyone I m setting up private mail server and to get better score on mail-tester it suggest me to setup rDNS How to I do it ? Properly my domain is reputation.help I m using cloudflare ...
-1
votes
1answer
161 views

unable to send email with php: Message accepted but never received [duplicate]

Here is the complete mail.log Jul 14 16:48:20 rezocoquin sendmail[5861]: v6EEmKCT005861: from=www-data, size=194, class=0, nrcpts=1, msgid=<201707141448.v6EEmKCT005861@rezocoquin.com>, relay=...
-1
votes
1answer
1k views

smtp relay shows temporary lookup failure

We deploy a new smtp relay server in ubuntu. When send test email from the root the mail flows properly. But when we use it as relay server it shows "temporary lookup failure" Where should we need to ...
-1
votes
2answers
992 views

Why does my server hostname appear in SMTP email headers sent from another domain?

I have seen some similar questions here however i am still to find a proper fix to this issue. The issues are as follow: I am trying to send emails from this email@domain2.com email address I ...
-1
votes
1answer
754 views

Why does nmap scan of same target smtp server show port 25 missing

I am configuring a new server, on a new network and struggling to get outbound SMTP to work to known mail servers. If I do an nmap scan from my existing server - port 25 shows up, but from my new ...
-1
votes
1answer
237 views

How does mail work, setting up own server

I am going to set up my own mail server using open source MTA - Postfix. In general I understand how everything works, but I still cannot find out some things. Here is diagram I am using for ...
-1
votes
2answers
894 views

how does _spf work on a DNS level?

i have noticed that google and other domains use _spf for their domain. i would like to how this works. would _spf be an a record that has multiple IP that would account for all mail servers or does ...
-1
votes
2answers
71 views

Is it possible that i use not mail.example.com,can i use just another like abc.example.com for my mailserver? [closed]

Two questions, two problems. I use cloudflare so I don't reveal my IP, there is a problem I can not use cloudflare for my mail server. Now is it so i am under DDOS because mail.example.com is exposed....
-1
votes
1answer
58 views

Which Email Server Expands the Recipient List into Many Emails?

When sending a message via a different SMTP outbound gateway, will a message containing multiple recipients in the BCC field be broken up into many messages by the originating server, or the server ...
-1
votes
1answer
31 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 ...
-1
votes
1answer
55 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 ...
-1
votes
1answer
340 views

Add a second IP to SPF record, from an external SMTP server [closed]

I would like to add the IP of an external SMTP server to an existing SPF record, which is looks like this: "v=spf1 a mx ip4:185.6.139.6 a:frey.mailpool.1.netmask.hu a:frey.mailpool.2.netmask.hu a:...
-1
votes
1answer
782 views

How to configure exim4 for both incoming SMTP for local delivery and relay for authenticated user

I want to use my exim4 mail server as local delivery for anonymous sender for my localdomains, and relay to everyone only for authenticated users. Is it possible?
-1
votes
1answer
435 views

IIS SMTP to create emails as file

Is it possible to configure IIS SMTP to receive emails from client and store into a file? Yes? How? My company does not allow email communication on our secure domain (long story). So in order to ...
-1
votes
1answer
4k views

DNS Setting for POP3 and SMTP email [closed]

I'm new to server configuration, I have used rented webservers a lot, but I tried venturing myself with a VPS to run my own web/email server. All is good, I installed VestaCP to help me with dealing ...
-1
votes
1answer
3k views

postfix/smtpd lost connection after AUTH from <server>[ip]

I try to send mail from a private LAN server to my private postfix server and I get this error, but I can't find its meanning: # /var/log/mail.log Jul 8 15:02:50 mail-srv postfix/smtpd[18222]: ...
-1
votes
1answer
25 views

Hosted email routing service while downgrading domain [closed]

I'm at a situation where I need to close a domain on Google Apps due to inactivity, while closing the domain I would be interested to preserve emails sent to that domain. I understand that my ...