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Mar
23
answered Windows based rsync server
Mar
23
answered Finding where something is installed on Ubuntu
Mar
23
comment How to reject/detect emails claiming to be from my own domain?
@user71061: I haven't tried to do this with sendmail or filters. It would be a simplification of a greylisting scheme. I have considered building an automatic IP blacklist, but haven't seen an indication that it would be a significant advantage.
Mar
23
revised How to reject/detect emails claiming to be from my own domain?
Added results of checking my database of email
Mar
23
answered How to reject/detect emails claiming to be from my own domain?
Mar
23
comment Rebuilding LDAP Index on Fedora
@Chris: That is likely the command. If not you will be notified. I still use /etc/init.d/slapd restart. It should tell you if the startup has been migrated to the newer form. You can use the ls -l command to see if the indexes get rebuilt. If they don't you will need to stop the service, rebuild the indexes, and then start the service.
Mar
22
comment Mail deliverability rDNS best practice
If the subdomains are used only for the email server, you can use the same TXT record for each (v=spf1 a -all). It will be a bit tedious, but you won't have to construct a record for each. If you mail server will be the MX for the sending domains you can use (v=spf1 mx ~all) for each. If the mail server IP address is the same as the corresponding web server's IP address you can use (v=spf1 a ~all) instead.
Mar
22
comment Mail deliverability rDNS best practice
Some sites, mine included, will verify SPF for the PTR record and/or HELO name (which should be the same). This is more effective in identifying spam, than than checking the envelope or header addresses.
Mar
22
answered Rebuilding LDAP Index on Fedora
Mar
22
comment Mail deliverability rDNS best practice
Try to consolidate all your outgoing email to one server. You should need only one email sub-domain for the email server to use in the HELO command. My web servers have a standard SPF record ("v=spf1 -all") as they don't send email. If you use the web server's address to send mail you could use "v=spf1 a:mail.example.com -all". The reply-to and envelope-from addresses are typically domains (although for automated email like a web-site they may be from a reserved sub-domain.)
Mar
22
comment Mail deliverability rDNS best practice
You should be able to configure your mail server to bind to only one Internet address. This makes configuration simpler as you only need to configure the DNS PTR for one address.
Mar
22
comment Mail deliverability rDNS best practice
Yes, rDNS is used to verify whether your server really is gmail.com when you say it is. (gmail.com is one of several frequently forged addresses used in HELO commands. The actual server names gmail uses are different.) Do use a subdomain for your mail server's address. Having a records for example.com, and mail.example.com returning the same address is valid and common. The PTR record should point to your subdomain. Using a domain as the mail server's HELO name is a marker that you are sending Spam.
Mar
22
comment Dnsmasq resolves local hostname to 127.0.0.1 all over the net
Not by default, but you can get your DHCP client to provide the required data. I am not sure why you would be serving a dynamic address for the host from dnsmasq.
Mar
22
revised Dnsmasq resolves local hostname to 127.0.0.1 all over the net
Clarify edit
Mar
22
answered Mail deliverability rDNS best practice
Mar
22
answered Dnsmasq resolves local hostname to 127.0.0.1 all over the net
Mar
21
revised Raising Exim4 smtp_accept_max on Debian / Ubuntu
Fix bullets
Mar
18
answered Raising Exim4 smtp_accept_max on Debian / Ubuntu
Mar
15
answered Email setup on dedicated servers
Mar
14
revised TCPWrappers still in use?
added 13 characters in body