Perfect Forward Secrecy (PFS) is a data encoding property that ensures the integrity of a session key in the event that a long-term key is compromised. PFS accomplishes this by enforcing the derivation of a new key for each and every session. Setup Dovecot Dovecot (at least from 2.1.x) already […]
I use on my servers ISPConfig, for IMAP and POP3 Dovecot is used. With Dovecot 2.x, the mails can also keep in sync between two servers. The replication is done via the Dovecot index files. So neither an error in the file system nor an accidentally deleted Maildir have a […]
If you see host aspmx.l.google.com[2607:f8b0:400d:c02::1b] said: 550-5.7.1 [2607:5300:101::79e] Our system has detected that this message does 550-5.7.1 not meet IPv6 sending guidelines regarding PTR records and 550-5.7.1 authentication. Please review 550-5.7.1 https://support.google.com/mail/?p=i…tication_error for more 550 5.7.1 information. h1si3408978qew.71 – gsmtp (in reply to end of DATA command) the destination dropped […]
To send outgoing mail with postfix for certain domains only over IPv6 or IPv4, only a few changes are required. The domains are registered in accordance /etc/postfix/transport examplev4.de smtp-ipv4-only: examplev6.de smtp-ipv6-only: /etc/postfix/master.cf: smtp-ipv4-only unix – – n – – smtp -o inet_protocols=ipv4 smtp-ipv6-only unix – – n – – smtp -o inet_protocols=ipv6 /etc/postfix/main.cf: transport_maps = hash:/etc/postfix/transport: Execute postmap hash:/etc/postfix/transport and […]
To prevent faked sender-adresses i recommend to use Sender Policy Framework (see www.openspf.org/Introduction). You can easily add the SPF-Modul from openspf.org to postfix. You need these three perl-modules Mail::SPF Net::DNS::Resolver::Programmable NetAddr::IP After installing the requied modules, get the SPF-modul from here. Extract the archiv and copy postfix-policyd-spf-perl to /usr/lib/postfix kopiert. […]
I use postscreen postscreen to prevent spam mails. Potential spam messages are rejected directly before they reach the server and the content must be scanned. You shouldn´t use postscreen if a Mail-User-Agents (MUAs) should be able to connect. Usually the TCP-Port 25 is only used for Mail-Transfer-Agents (MTAa) since MUAs […]
Imapsync itself is a great tool. I find the price of 42.00 EUR bit high to have to move “only just” quickly a mailbox with a few hunder MB. Thanks to google the problem is solved…. zypper ar http://download.opensuse.org/repositories/devel:/languages:/perl/openSUSE_11.4 perl zypper ar http://download.opensuse.org/repositories/home:/pheinlein/openSUSE_11.4 imapsync zypper ref zypper in imapsync perl-Date-Manip […]