哪些主流邮件客户端实际采用DNS SRV自动配置（基于RFC 6186）

First, let's recap how RFC 6186 works for email auto-discovery—it uses DNS SRV records to define server settings for different email protocols. Here's a concrete example of what those records look like for a domain mydomain.com:

SRV _submission._tcp.mydomain.com 0 1 587 mailserver
SRV _imap._tcp.mydomain.com 0 0 0 .
SRV _imaps._tcp.mydomain.com 0 1 993 mailserver
SRV _pop3._tcp.mydomain.com 0 0 0 .
SRV _pop3s._tcp.mydomain.com 10 1 995 mailserver

(Entries with 0 0 0 . disable unencrypted IMAP/POP3, forcing clients to use SSL/TLS-enabled variants.)

Now, let's break down what we know about support in popular clients:

Clients confirmed/presumed to NOT use RFC 6186 #

• Outlook: Relies on its proprietary AutoDiscover mechanism (usually via autodiscover.mydomain.com HTTP endpoints) instead of RFC 6186.
• Mozilla Thunderbird: Uses its own auto-configuration system, often pulling from Mozilla's central config database or requiring manual input—it doesn't implement RFC 6186.
• iOS Mail App: Appears to lack native RFC 6186 auto-discovery functionality (this isn't fully confirmed). You can automate setup for iOS devices using a mobileconfig profile instead.
• Android Native Mail App: Does not support RFC 6186-based auto-discovery at all.

Clients that may support RFC 6186 #

Unfortunately, there's limited clear public documentation confirming which mainstream clients fully implement RFC 6186. Some smaller or open-source email clients might support it, but for major day-to-day tools, the above list covers those we know don't use the protocol.

If you're testing support for a specific client, the most reliable way is to set up the SRV records as shown and check if the client automatically pulls correct server settings without manual input.

内容的提问来源于stack exchange，提问作者Roel van Duijnhoven