Off topic: smtp HELO question

[John Johnstone]

On 3/6/17 2:53 PM, Quartz wrote:

> I get a 7/10 (apparently because I never set a SPF to hook my mail
> service to my domain?).

If the fundamentals of your outgoing mail server aren't good enough, any 
hair-splitting differences with submission are irrelevant.  I'd not 
spend any time worrying about your Thunderbird configuration unless you 
have evidence that it's a problem somewhere.

You need to be especially careful that you have correctly implemented 
SPF or DKIM.  Some mail servers will regard incorrect configurations 
worse than none.

If your "external address floats around depending on what my ISP gives 
me" means that your mail server has an address in an ISP's DHCP address 
space, you're at a major disadvantage right there.  Many mail servers 
will reject or score badly mail that comes from a dynamic IP.  If you 
can't get a domain name of your choice (e.g. mail.your-domain-name.tld) 
assigned to your external IP, even if it is static, that's a major problem.

You can lookup your IP at Spamhaus and if it's listed in the PBL you're 
almost guaranteed to have delivery problems.  If you're operating your 
own mail server your volume may be too low to have an meaningful 
reputation but you can check your IP at someplace like SenderBase.

You can do a web search on "email delivery".  Sad to say but it's not a 
trivial topic in today's world.

-
John J.