Questions tagged [starttls]

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3answers
130 views

Why is port 587 preferred over port 465 in SMTP?

I have recently been developing a C# client which sends emails via a SMTP server. However I have been as to what the different terms ment, like: STARTTLS/TLS/SSL... I had a faint idea of what they ...
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1answer
32 views

Gmail failing to accept TLS

I recently set up a postfix mail server. Testing it with other domains, everything seems to work well. However, when my server tries to send messages to gmail, they are marked as spam, with the red ...
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1answer
58 views

Are SMTPS and IMAPS ports really deprecated?

I've read that STARTTLS command was added and intended to deprecate the SSL ports. But even major mail servers like google still use SSL ports and even don't allow us to use classic ports with ...
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1answer
121 views

How to read an OpenSSL cipher suite list

hMailserver is an open source Window e-mail server. For incoming e-mail it supports STARTTLS with the help of OpenSSL 1.1.1. It allows configuring the cipher suites, the default is: ECDHE-RSA-AES128-...
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0answers
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On connection test Sendblaster complains “503 starttls command used when not advertised” but sending logs show that starttls was performed

I am using an SMTP which relays messages from Sendblaster. We do not have any username + password authentication. Rather the admin chose to have a whitelist (in the Exim config file) of IP address and ...
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1answer
439 views

Postfix 3.3.1 on Centos 8 can't enable TLSv1 or TLSv1.1

I recently migrated my main mail server to a new one, the old one had been running for almost 10 years and was the production server for around 20 domains and over 40 mailboxes. Everything went well ...
2
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1answer
251 views

Getting postfix to relay SMTP/SSL/TLS to Charter/Spectrum

I'm running Postfix on Debian as an MX for a small LAN and trying to get SMTPS working with mobile.charter.net over port 587. I followed a few links off google for setting this up along with a post on ...
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0answers
523 views

NSS-LDAP not working over TLS: do_open: do_start_tls failed:stat=-1

I'm using NSS-LDAP for authentication. Without TLS, everything works fine. Once I enable TLS (StartTLS) with a self-signed certificate, which I have added to the client, NSS-LDAP won't connect to the ...
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1answer
121 views

Outlook 2010 can receive but not send - authentication fails - Thunderbird works

After the mailserver was upgraded from CentOS6 to CentOS 7, Outlook 2010 on Windows 7 can receive email but not send, the error says authentication failed. However Mozilla Thunderbird can receive and ...
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1answer
230 views

Deny non TLS incoming mail with postfix and force certificate check

I want to deny non TLS incoming mails on my postfix server. Here is what i've done: smtpd_tls_security_level = encrypt smtpd_tls_auth_only = yes I do not really understand the difference between ...
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1answer
14 views

Will msmtp fallback to unencrypted connections if encrypted connections fail?

My ~/.msmtprc config file says to connect to a server on port 25 with tls on and tls_starttls on. Is there a risk that, if the encrypted connection setup fails for some reason, then msmtp will ...
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1answer
3k views

Postfix 3.4.9 SSL issues — no shared cipher from servers using TLSv1

Edit 1: I've narrowed it down to TLSv1 that both servers listed below (no others have failed yet) are attempting to use. I'll be contacting their webmasters requesting they stop using an insecure ...
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0answers
67 views

Apache and TLS mode - password in plain text in wireshark

My apache.config: LDAPTrustedMode TLS LDAPTrustedGlobalCert CERT_BASE64 /etc/pki/tls/certs/ca.cer AllowOverride None Options None #Order allow,deny #Allow from ...
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1answer
340 views

TLS from unknown: No client certificate presented

We have setup a windows server virtual SMTP (under IIS6 manager). In the SMTP settings, TLS encryption is enabled, fqdn field is "sharepoint.mycompany.com". In the server's cert store "personal" ...
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1answer
84 views

CentOS OpenLDAP STARTTLS wierdness

I am having a very strange problem configuring my CentOS OpenLDAP for STARTTLS. Here's what's going on. I have a bunch os scripts that I use to configure my system. I do this to document a machine's ...
2
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1answer
585 views

Do any reputable mail servers require STARTTLS encryption for SMTP delivery?

Are there any large, reputable MTAs (like gmail, hotmail, icloud, etc) that will bounce mail or otherwise fail to deliver if the receiving MTA doesn't support STARTTLS? Put another way, will ...
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1answer
115 views

Postfix bounce when unable to validate TLS option

I'm using postfix as mail transfer agent on my mailgateway to send and receive emails. Because I'm communicating with sensitive information I'm using the tls options to validate the receivers mx. He ...
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0answers
143 views

Server 2012 R2 SMTP service not sending mail to non TLS servers

We have SMTP virtual server on server 2012 R2 server. I have configured it to use TLS connection. We do have real sertificate etc. Everything works fine except mail that is going to mail server which ...
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1answer
500 views

Ambari sync with LDAP using StartTLS

I'm facing an issue to sync Ambari with a LDAP server using StartTLS and a self-signed certificate. Ambari server and ldap server are both running on the same machine. I've followed the steps written ...
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1answer
2k views

No STARTTLS with Dovecot and Postfix

I have done a lot of searching and am not finding a solution. I had to reload Mageia 6 on my email server. I am using dovecot-2.2.34-1.mga6 and postfix-3.1.6-1.mga6. Openssl is openssl-1.0.2o-1....
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1answer
88 views

I'm able send email via Thunderbird, but not via my own app. The email settings are identical

I have my Postfix server. I can send email via it with no problem using Thunderbird. For smtp I have: port - 587 Normal Password STARTTLS However, I can't send an email through the same server via ...
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1answer
318 views

Trying to make submission (587) work - Exchange 2016

I'm trying to allow the authenticated relay (Client Frontend connector) to process requests from LAN and internet, but I'm struggling so far. First, I have linked this connector to my SSL wildcard ...
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3answers
5k views

Client did not present a certificate (Postfix)

I have postfix SMTP relay which have been configured with TLS option. Now just realized when sending email to gmail (for example) using Microsoft outlook,found out this "Client did not present a ...
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1answer
4k views

Postfix STARTTLS encryption before authentication

I'm trying my best to configure Postfix with STARTTLS using port 25. Now the problem is STARTTLS is not working on port 25. 250-VRFY 250-ETRN 250-XXXXXXXA 250-AUTH PLAIN LOGIN 250-...
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1answer
181 views

Mail server: Does /etc/mailname have to match SSL certificate CN?

I set up a web and email server on a VPS that uses apache2 with multiple virtual hosts and postfix, dovecot, and roundcube for the email server. I am getting an authentication failure when trying to ...
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1answer
2k views

postfix tls not reading or finding key

I've been having issues sending mail to my server, and there are indications of TLS errors (mostly from the maillog). What I've tried: Ensuring that postfix / dovecot can read the certificates (made ...
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1answer
137 views

Sendmail process crashes as soon as STARTTLS is received

I just upgraded my server from FreeBSD 10.3 to 11.1. It's now running Sendmail 8.15.2 and OpenSSL 1.0.2k-freebsd 26 Jan 2017. Since the upgrade, sending mail to my server is failing. I cranked up ...
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2answers
959 views

Is TLS necessary for port 25 for MX delivery?

I am in the process of implementing a new Postfix implementation on an existing environment which is extremely old. While doing so I am requiring all clients to connect securely on either 465 or 587 ...
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1answer
309 views

SMTP Server (Exchange 2003) hangs up on client after STARTTLS command after adding cert

I am stumped on this. I have Exchange Server 2003 still in use. I created a valid LetsEncrypt SSL cert, and successfully imported the pfx in my Default SMTP Virtual Server properties, Access tab. ...
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1answer
45 views

Does DNS need to be pointed toward the right sever, for SSL to work

So the issue I'm having, is with a new mail server I've been setting up. Now it seems to work fine when not using ssl. And if I try using ssl, with a mail client like airmail it says host name ...
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2answers
4k views

How can I decrypt STARTTLS communication over SMTP in a packet capture (if I have the private key)?

For the purpose of troubleshooting, I need to see what an email looks like when it's sent to my sendmail server via SMTP. The upstream server requires the SMTP connection to use STARTTLS so a packet ...
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3answers
1k views

SNI like equivalent for starttls

I am trying to host two seperate domains on one IP address. I want to be able to determine from the STARTTLS command which certificate was being requested and forward to a different mail server based ...
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1answer
717 views

Disabling SSLv2 in Courier IMAP

I'm attempting to disable SSLv2 support (amongst other things) in Courier on Linux. In /etc/courier/imapd-ssl I have: TLS_CIPHER_LIST="HIGH:!MEDIUM:!SSLv2:!LOW:!EXP:!aNULL:!ADH:@STRENGTH:!3DES" ...
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1answer
7k views

Can't connect to Exchange 2016 with port 587 TLS

Hi everyone i'm having issues with SMTP notifications connecting on port 587 with TLS. Right now I have an internal Exchange 2016 server and all email works great. I have a few customers who have ...
2
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1answer
624 views

Postfix TLS encryption: smtp_* vs smptd_*

I am really confused about the postfix TLS settings. There are in each case settings for private keys and public keys. smtpd_tls_cert_file = smtpd_tls_key_file = smtpd_* And smtp_tls_cert_file = ...
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2answers
2k views

Configure OpenLDAP using GnuTLS with TLS=required

We have an openldap server and don't want to allow unencrypted communication, so acceptable is either tls over port 389 (starttls) or ssl over 636 (ldaps). As we use slapd.conf for configuration, ...
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0answers
394 views

Postfix TLS Roundcube problems

im writing this because i have a problem when i try to test SMTP with Roundcube. Before i had no problem with Postfix ou Dovecot. It seems like it's a TLS problem : SMTP Test When i look in my log ...
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1answer
880 views

How to force postfix to deny all non TLS queries?

I have a server with postfix and a plain text authentication. It accepts both TLS and non-TLS authentication. How can I force the server to deny all non TLS queries so that the mail users never send ...
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3answers
31k views

Postfix configure to use TLSv1.2

I start build my first cloud server: Ubuntu 16.04 with postfix. Question is how can i configure postfix to use TLSv1.2 when i send mail from my webshop? When my webshop sending mail to my postfix ...
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1answer
1k views

Unable to send email from Command Line in Postfix (warning: TLS library …)

I configured postfix with ssl/tls. and created an smtp. However I am unable to send test email and/or login. "Text below first defines error log (different attempts) and then configuration files." ...
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1answer
61 views

Does anything changes for a client in the API communication after the command STARTTLS is sent and a response received

I'm trying to understand how the command STARTTLS in IMAP works exactly and what becomes different when it's sent. After I've sent the command "STARTTLS" before login process and received the response ...
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2answers
3k views

Exim client not issuing STARTTLS when connecting to smarthost

I have a Debian8 server running exim4 that sends outgoing mail by smarthost through NameCheap's mail.privateemail.com smtp server - or at least it use to. After a recent update, the server no longer ...
2
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1answer
9k views

ssmtp settings for namecheap: Invalid response SMTP Server (STARTTLS)

I am trying to configure ssmtp to use the namecheap smtp server to send emails. My current configuration: root=my@email.com mailhub=mail.privateemail.com:465 rewriteDomain=email.com hostname=email....
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2answers
7k views

How to force STARTTLS in Exim?

I am learning to set up a mailserver. I got it working with postfix, now trying the same configuration with Exim. How can I force a client to take up only STARTTLS connection for SMTP outgoing ...
2
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1answer
604 views

Properly Configure Postfix to be secure (SASL + TLS)

I've followed online tutorials online to setup my mail server with SASL and TLS, and amavis. It all seems to works - except i can send mails even if i don't authenticate first - which is not good. I ...
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1answer
960 views

Thunderbird STARTTLS fails connecting to Cyrus-IMAP 2.2.13

Today all of a sudden my Icedove mail clients (38.7.0) ceased working using STARTTLS after I renewed the server certificate. Plain text IMAP works fine. The server logs STARTTLS negotiation failed ...
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2answers
2k views

I can't send a message with postfix. Error: “Must issue STARTTLS first”

I am novice with postfix. My goal is to use it with fan/nagios/centreon in order to receive notifications. I have tried many solutions found on this forum or thanks to google, but it didn't resolve my ...
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2answers
10k views

Postfix “Trusted TLS connection established” but “Server certificate not verified”

I´m using a Postfix TLS Policy to enforce TLS for outgoing email. Unfortunately in some cases the certificate verification fails and I don´t know why. For instance, this is an excerpt of my TLS Policy ...
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0answers
1k 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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1answer
773 views

Enabling STARTTLS for all on Postfix with Zarafa

I ran into a problem which I just cannot solve with just googling it - I need some expert help. My company runs it's own mailserver (postfix with zarafa groupware). We're an insurance company so we ...