0
votes
1answer
85 views

SMTP Connection disconnecting after “STARTTLS”

We're having issues with our mail server. Basically some emails from external networks are not being accepted by the mailserver. After some debugging using telnet and looking through the logfiles, it ...
-1
votes
1answer
32 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
vote
2answers
244 views

Postfix, TLS and StartSSL certificates

I recently changed my postfix installation to use TLS with a certificate issued by StartSSL. I then ran SMTP and TLS checks with no errors or warnings. Everything seemed to work fine. My problem now ...
6
votes
2answers
499 views

Display a TLS icon for messages that are TLS secured (Outlook)

One of my colleagues at a large financial institution has customised Lotus Notes to show a TLS icon for messages that are TLS secured. I'm interested in imitating this feature in Outlook, and believe ...
0
votes
0answers
113 views

Set Windows Server 2008 R2 SMTP for Opportunistic TLS

I use a Windows 2008 R2 server for sending (relaying) outbound emails to clients. Many of these clients are now requiring TLS connections to send them email. To date I have set up a an SMTP "Remote ...
0
votes
2answers
3k views

Postfix & Gmail: Authentication Required error

I configured Postfix using this guide. When I send a test E-Mail I get the following error message: May 23 15:36:26 VM11 postfix/smtp[15321]: connect to smtp.gmail.com[2a00:1450:4001:c02::6d]:587: ...
0
votes
1answer
176 views

Can't send mail through ssl with my virtual domains from an external webmail

I having issues with postfix to send mail through SSL from an external webmail. I have several domain setup on my server configured in postfix with mysql. When I send mail with my main domain ...
1
vote
1answer
213 views

Is it possible to configure sendmail to require/use certain ciphers during TLS negotiation?

CentOS 5.x | SendMail I'd like sendmail to use a specific cipher when negotiating a TLS session with a specific remote MTA/domain. Is that possible? I'm aware that a minimum bit strength can be ...
1
vote
1answer
498 views

Two Exchange 2003 servers, Internet SMTP Connector using port 587 on smarthost: no longer internal connectivity between the Exchange servers

To summarize: I set things up (this is a virtual test/tutoring environment), broke internal connectivity by introducing Internet mail connectivity, figured out where the problem was, but now I'm ...
0
votes
2answers
362 views

IPTables Rule for Google Apps SMTP

I am trying to add iptables rule to allow traffic on ports 465 & 587 to google apps smtp servers. But I got not luck. My WHMCS installation works fine with google apps when I turn off iptables but ...
1
vote
2answers
594 views

Using nc.exe (NetCat) to send emails to secured SMTP server (TLS)

I used to send emails to unsecured SMTP servers using nc.exe utility (Windows port of NetCat) and now I need to send the same emails to a secured SMTP server (TLS). What additional parameters do I ...
2
votes
2answers
277 views

How do I log tls-encrypted smtp traffic?

I'd like to know what my local postfix says to the Amazon SES smtpd after the STARTTLS. In plain text, so I can understand it. Amazon SES requires TLS, so I can't temporarily turn it off. I currently ...
0
votes
1answer
228 views

What's the difference between Postfix SMTP server and client in regards to TLS Support?

I need to implement TLS tunneling in my Postfix so that when needed it can use TLS certification (when trying to send mails to the domain xxxx.xx, their servers will ask mine to establish a TLS ...
2
votes
1answer
370 views

Opportunistic TLS for incoming mail with masked SMTP banner

I have a mailserver with opportunistic TLS enabled (Postfix smtpd_tls_security_level = may), however the SMTP banner is being masked by SMTP fixup on our FWSM. Before I disable this masking, is the ...
4
votes
4answers
6k views

Disable SMTP AUTH on Port 25

Due to PCI-DSS, we are required to disable plaintext authentication. We've achieved this by encapsulating communications between our mail server and clients with TLS on port 465. The problem lies in ...
0
votes
1answer
179 views

Configuring postfix to use TLS for a particular server?

Running kubuntu 10.04 on my host, let's call it alpha. I've got postfix as my system MTA. I've got crons running on alpha that need to send email to a remote host, let's call it mailhost. I cannot ...
2
votes
2answers
2k views

Postfix: Allow unauthenticated incoming mail, but only authenticated outgoing mail?

I'm new to the world of mail server's and have been working on setting up my own via Postfix on Ubuntu 11.10. So far, I have SASL authentication working over TLS so that's good; I'm worrying about ...
2
votes
0answers
220 views

Forcing IIS virtual smtp server to verify outgoing TLS certificate

I am in a situation where a web application is using the IIS virtual SMTP server to send out email. The IIS virtual SMTP server is then configured to send all mail out through a smarthost, over TLS ...
0
votes
1answer
116 views

Why is the SMTP service locking the files for several hours?

We are currently using the SMTP service in IIS 6.0 to send mails. All incoming relay mails are monitored by another service which processes the relay mail and deletes/moves it. It works fine! We have ...
2
votes
2answers
524 views

Is there a way to completely disable outbound opportunistic TLS support in SendMail?

CentOS 5.x SendMail 8.14.4 An overzealous network security feature is causing TLS negotiations to fail when my Sendmail server tries to talk to external hosts. This is causing sendmail to constantly ...
4
votes
1answer
2k views

Postfix TLS over SMTP - RCPT TO prompts renegotiation then 554 5.5.1 Error: no valid recipients

I've setup ispconfig3 on my debian six server, and here is a little smtp over ssl: The server is postfix AUTH PLAIN (LOL!) 235 2.7.0 Authentication successful MAIL FROM: lol@lol.com 250 2.1.0 Ok ...
0
votes
1answer
564 views

Can't send email via SMTP in Postfix/Ubuntu, but can receive it fine using IMAP/POP3

I'm running Ubuntu, have Postfix installed. Followed https://help.ubuntu.com/community/Postfix to the letter. I can receive email via IMAP and POP3 perfectly in Thunderbird. But when I try to send ...
4
votes
1answer
1k views

Exim TLS and Secure SMTP

I'm in the process of converting an existing mail server to support encrypted SMTP for our clients, but I've run into this brick wall with very little useful log data to help me forward. Everything ...
2
votes
2answers
125 views

Connecting to Postfix via TLS

First off, I'm a programmer without much experience in programming with network protocols. That being said, I'm attempting to connect to a Postfix SMTP server using a secure connection. The ...
-1
votes
2answers
95 views

Looking for a simple SMTP server that supports TLS and can run on Linux [duplicate]

Possible Duplicate: SMTP server for Linux with simple configuration I'm looking for a simple SMTP server that I can run without too much installation hastle and that which can also support ...
2
votes
1answer
3k views

How to change sendmail fallback behavior if TLS handshake fails?

I have a CentOS 5.x server running sendmail that is failing to negotiate TLS with SOME various recipient servers. I'm looking into it. In the meantime though, I've noticed that sendmail will NOT ...
0
votes
1answer
157 views

Configuring sendmail to only use starttls in client mode

Is it possible to configure sendmail so that it will only connect to a remote smtp server when STARTTLS is offered there? I so - how do I do it?
1
vote
2answers
8k views

Is it possible to set up Exchange so that all outbound emails to a specific domain must go through TLS?

And that, if that domain doesn't have TLS turned on, email-sending fails? I've been looking at setting up SMTP send connectors, but there doesn't seem to be an option to enforce TLS?
1
vote
2answers
694 views

iptables only allow smtp connections with start tls

Is it somehow possible to block/abort unencrypted smtp connections with iptables? effectively rejecting all connections which dont do a start tls.
-1
votes
2answers
417 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 ...
0
votes
3answers
4k views

Postfix & TLS is configured correctly, but Thunderbird throws cryptic errors when trying to send email via SMTP & STARTTLS?

I've just recently installed CentOS 5.5 and Postfix for the first time ever. I've followed 2 different tutorials which are supposed to enable TLS on the SMTP server. Both of which told me to create a ...
0
votes
2answers
267 views

Do I need to enable TLS support for postfix?

I need to send out notifications from my web-app and I've setup postfix as a null client on my server. So in my /etc/postfix/master.cf I have commented out the lines #smtp inet n - ...
0
votes
1answer
523 views

Can't access Postfix TLS/SSL

I have set up my Postfix, with TLS/SSL, correctly. Every test on the machine itself (with telnet) runs fine. However, when I want to access the server from somewhere else, it fails. So port 587 and ...
3
votes
1answer
1k views

IIS6 SMTP and TLS on outbound connections

In the options for setting up the SMTP server hosted in IIS, there exists an option to enable TLS on outbound connections which I want. However I also want it to be able to fallback to clear text in ...