Minimum PostFix configuration for sending emails only?
The postfix documentation tells you exactly what you need to do.
email-server
Are separate dns records necessary for web and mail on a single server?
Yes, it would be possible, but you will lose some important advantages if you choose to do so: If you point all services to the same DNS name, you can’t put them onto separate servers any more without reconfiguring any client that refers to them. As an example: With different names, when the load on … Read more
Do you use postfix or qmail and why [closed]
afaik qmail is deprecated in most distros, so you’ll probably have to build from source and forget about easy apt/yum style updates. If you still want to go with qmail, qmailrocks.org is what got me through a setup with minimal brain damage. On the other hand, postfix seems to be replacing sendmail more and more, … Read more
How to determine a reasonable attachment size limit?
“Email is not intended for file transfer!” In all seriousness, I set mine at 10MB, any higher and you might get rejections from remote SMTP servers. If your company/client does use a lot of larger files, I might be convinced to set it at 15 or 20MB but no higher than that. I instruct clients … Read more
What is the best method for sending email on behalf of my clients’ domains?
Excellent question. I’ve just spent several hours researching the same thing. I had previously deployed numerous websites that use Option C for email forms (mainly out of naivety), but we are experiencing an increasing number of delivery issues. Email providers are gradually tightening up on things. For example Yahoo recently changed their DMARC policy to … Read more
How do I temporarily suspend mail delivery to a specific domain (non-local) with Postfix?
Put messages in a HOLD state /etc/postfix/main.cf: smtpd_recipient_restrictions = … check_recipient_access hash:/etc/postfix/hold /etc/postfix/hold: gmail.com HOLD blah.com HOLD Make sure you run postmap hash:/etc/postfix/hold whenever you update the file. If you want to release all messages on hold, use postsuper: # postsuper -H ALL
Spamassassin flagged something as spam that is not spam. How do I tell it so?
There is both specific and general advice that may be useful in this case. Specific The underlying problem here is that Garuda Airlines, bless their little cotton socks, are sending confirmation emails that bear many of the hallmarks of spam. The subject line is VERY SHOUTY, they send HTML-only emails which contain quite lot of … Read more
PTR record (rDNS) for multiple domains on a shared IP address
Reverse DNS can only really have one name — if you list more than one, DNS will just round-robin between them. So you just have to pick one “official” name for the server and always use that. All the other domains are, in essence, just aliases to the original. Most services don’t care what the … Read more
Setting up SPF and DKIM records of a subdomain
Like in the answer from BillThor, you probably NEED to set up SPF and DKIM for the example.com i.e. the hostname used in email addresses user@example.com, where mail.example.com is only a MX for the domain. But, to answer the exact question… Unlike claimed on another answer, it is possible to set up both SPF and … Read more
How to collect bounces in postfix
The exact answer to your question (handling the bounce-xxx@example.com address) depends on how your server is configured to receive mail. If example.com is the virtual domain the best you can do is collect the messages in the bounce@example.com mailbox (assuming recipient_delimiter = -). If example.com is the locally delivered domain for the server (mail is … Read more