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Questions tagged [starttls]

The tag has no usage guidance.

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1answer
29 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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0answers
23 views

how create domain_certfile by ejabberd on iis?

how can I create a tls certificate? Honestly, I have no idea how the whole thing is going, but now I have an idea. I want to use for a site in iis??
1
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1answer
28 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 ...
1
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3answers
233 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 ...
0
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1answer
111 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-...
1
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1answer
80 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 ...
0
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0answers
18 views

Does creation of a connected account in Outlook webmail require insecure SMTP?

I'm trying to add an e-mail account in a server I manage (Postfix + Dovecot) as a connected account in my Hotmail account. If I select a send-only SMTP account, I don't see any options for SSL/TLS/...
0
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1answer
126 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 ...
3
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1answer
50 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
116 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 ...
0
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1answer
81 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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0answers
121 views

TLS encryption certificate

Can you please help me on upgrading or enabling the TLS on my VPS that is running CentOS 6, I tested many commands and solutions on internet but none of them worked, the TLS is needed on the email ...
0
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1answer
41 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 ...
7
votes
2answers
812 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 ...
2
votes
2answers
406 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 ...
1
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0answers
93 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" ...
0
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1answer
2k 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 ...
0
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1answer
106 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 = ...
3
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2answers
747 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, ...
1
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0answers
176 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 ...
0
votes
1answer
192 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 ...
3
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3answers
6k 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 ...
0
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1answer
263 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
48 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 ...
0
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2answers
1k 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 ...
1
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1answer
3k 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....
2
votes
2answers
3k 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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0answers
287 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 ...
1
vote
1answer
482 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 ...
0
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2answers
923 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 ...
5
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1answer
5k 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 ...
1
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0answers
487 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 ...
1
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1answer
300 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 ...
0
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1answer
215 views

STARTTLS sendmail handshake failures on SMTP and retries

I'd like to gracefully handle sendmail STARTTLS handshake failures. On outgoing mail, it would be best if there were an immediate retry without STARTTLS in the case of failure. On inbound mail, ...
3
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0answers
65 views

Postfix STARTTLS works in LAN but not externally

if I connect in LAN on port 25 to my mail server, it offers STARTTLS telnet mailserver.com 25 Trying 192.168.0.x... Connected to mailserver.com Escape character is '^]'. 220 mailserver.com ESMTP ...
2
votes
1answer
353 views

Validate email address at my own domain with gmail

I need to have the ability to send email using gmail's web interface, but have them appear to originate from my own domain instead of originating at a gmail address. In order to do this, gmail asks ...
1
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0answers
46 views

Are there issues in whitelabling a SMTP server (not mine) with an A record that doesn't match 200 helo?

I know that a CNAME and a MX record can't exist on the same host. In this scenario I'm using A records to manage SMTP for 350 DNS domains. companyA.com MX myAlias.whitelabel.com companyb.com MX ...
2
votes
1answer
356 views

SVN Edge not authenticating correctly with domain controller

SVN Edge (version 4.0.10-3880.131) not authenticating correctly with domain controller. I have SVN Edge setup and working perfectly when I use LDAP Security Level of NONE.. However when set to SSL, ...
1
vote
1answer
273 views

Drop non-TLS connection on EXIM

How to restrict access to EXIM to clients with STARTTLS? I want to be able to drop non-TLS connections. Current setup: tls_on_connect_ports = 465 tls_advertise_hosts = * tls_certificate = /some/...
2
votes
1answer
567 views

How to mitigate STARTTLS MITM (downgrading and forged certificates) between email servers?

I'm not as technically inclined as most on this site so please keep that in mind. I wanted to learn more about email security so I did some research and everything is according to my understanding, ...
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0answers
374 views

How to make Postfix SMTP TLS Optional?

Just did an [emergency] conversion from qmail to postfix last night - but now I'm getting people complaining that mail client errors are showing up stating "no available encryption methods available" ...
0
votes
1answer
619 views

Dovecot STARTTLS fails using fetchmail

I currently try to get my own mail server up and running. So far everything seems fine as I am able to connect to this mailserver using thunderbird. The only thing I have to do is accepting my own (...
1
vote
1answer
65 views

Verify TLS encryped communication when querying LDAP server?

I have a web application (not hosted on windows) that authenticates users by querying an LDAP server (a windows domain controller). The app is configured to use STARTTLS to encrypt communication with ...
-1
votes
1answer
379 views

Gitlab with OpenLDAP secured with TLS

I have a working, secure OpenLDAP server running at: auth.<company name>.com I also have a reader account that Gitlab can use: cn=Reader Reader,ou=users,dc=auth,dc=<Company name>,dc=com ...
0
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1answer
119 views

SMTP doesn't work on distinct machine [closed]

I'm trying to setup TLS e-mail on remote machine, but it doesn't work. Trying to send e-mail on my local machine (Windows 7 x64 locale ru-ru): 16:33:18 CONNECT : Looking up host name mail....
1
vote
1answer
8k views

Postfix STARTTLS only on port 25

I want to enable STARTTLS on port 25, but for unknown reasons it only works on port 465. master.cf: smtp inet n - - - - smtpd -o syslog_name=postfix/smtp -o ...
2
votes
1answer
6k views

How to disable SSLv3 in Postfix 2.11?

I just noticed (by some online check tools) that my mailserver may allow SSLv3 and updated my configuration. My current config in Postfix 2.11.2: # inbound smtpd_tls_security_level = may ...
2
votes
0answers
3k views

LDAP with TLS: connect error(-11)

I configured OpenLDAP and today I've configured the TLS for more security following these guide lines: Configure OpenLDAP with TLS=required Modifying the cn=config.ldif with config file: dn: cn=...
5
votes
1answer
10k views

Postfix Recipient address rejected: Access denied Error

Trying to use zend mail smtp to send email from my php app login authenticated and give me this constant error I don't have to deal with I look into de 36 question here on serverfault.com changing ...
2
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0answers
612 views

Does Google require TLS on port 587? Exchange 2010 SMTP has mail sent to GMAIL backed up in queue

Exchange 2010 SMTP has mail backed up in queue. Any email sent to Gmail sits in the queue while any email sent to another personal domain which has email filtering enabled errors, "asp.reflexion.net ...