Needed to add RBL checking into sendmail as the machine was under attack by some smtp botnet. RAQ550s had no inbuilt RBL support so had to update the sendmail.cf manually.
URL: http://www.cobaltuserslist.com/CobaltUsersList/Sun-Cobalt-Users-List-76800.html
The example is a bit old… the RBLs I used are: cbl.abuseat.org , bl.spamcop.net, sbl.spamhaus.org
Cobalt list post:
RBL (Realtime Blackhole List) filtering allows your sendmail installation
to [...]
Tags: Linux · Operating System · Protocols · SMTP · Uncategorized
Occasionally you may want to test your mail server to see if it accepts unauthenticated mail to be relayed.
These URLs allow you to do this:
http://www.abuse.net/relay.html
http://www.dnsgoodies.com/
http://www.checkor.com/
To quickly check that SMTPS is running on a remote server you could run:
openssl s_client -connect hostname:465
Great link to information regarding testing SMTP AUTH:
http://qmail.jms1.net/test-auth.shtml
To test SMTP AUTH I did the following:
[server]# perl -MMIME::Base64 -e ‘print encode_base64(“\000test\@domain.com\000testpassword”)’
AHRlc3RAZG9tYWluLmNvbQB0ZXN0cGFzc3dvcmQ=
[server]# perl -MMIME::Base64 -e ‘print decode_base64(“AHRlc3RAZG9tYWluLmNvbQB0ZXN0cGFzc3dvcmQ=”)’
test@domain.comtestpassword
Then connect to the server and try putting in the above SMTP AUTH details:
[server]# telnet localhost 25
Trying 127.0.0.1…
Connected to localhost (127.0.0.1).
Escape character is ‘^]’.
220 localhost ESMTP
ehlo testing
250-localhost
250-STARTTLS
250-PIPELINING
250 8BITMIME
AUTH PLAIN AHRlc3RAZG9tYWluLmNvbQB0ZXN0cGFzc3dvcmQ=
235 go [...]