DKIM+phpmailer dkim=neutral (bad format) [email protected] How to do it right?

Question

PHP

Trying to sign a DKIM bcgjkmpez email for a phpmailer mailing list. I’ll make a reservation right away that the version was used both 5.2.9 and 5.2.14.
Instructions for finishing phpmailer'a took here gaalferov.com/blog/nastrojka-dkim-spf-phpmailer.html and completely "observed".
SPF and DKIM have been registered in DNS for a long time (I use mail for the domain from Yandex). DKIM record (Yandex automatically registered it when it delegated the domain):
mail._domainkey TXT v=DKIM1; k=rsa; t=s; p = MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDd + f6E2DnhdeRjFNNlepZPFvv69PTBwmc5uVUyzKR5wlPtaZZmtksl / eJKKtHdlDdv8W + n2HBdoq8bTDJ6KQq31sunz48qW5UxxoekMcwoyNJdZx8mkHRFg + jOoQzU5Qg2OnSCwtw2ZhgwFJuIx8KY1diGyB7T / R + DD646nEPXmwIDAQABthe

scripting run from subdomain sub.domain.ru
The letters following headings:

according to gmail:
Received-SPF: pass (google.com: domain of [email protected] designates XXX.XX.XX.XX as permitted sender) client-ip=XXX.XX.XX.XX;
Authentication-Results: mx.google.com;
spf=pass (google.com: domain of [email protected] designates XXX.XX.XX.XX as permitted sender) [email protected];
dkim=neutral (bad format) [email protected]
according to Yandex.mail:
Authentication-Results: mxfront5o.mail.yandex.net; spf=pass (mxfront5o.mail.yandex.net: domain of domain.ru designates XXX.XX.XX.XX as permitted sender) [email protected]; dkim=neutral

Where to dig? Thank you.

Answer 1

First, what private key are you using for DKIM? It is embarrassing that you write that Yandex, and not you, prescribed the entry in the DNS for you, but at the same time you send it from your server. Those. you had to either take the private key that Yandex generated for you (which can only be obtained by contacting support), or use your own, but then you had to create a second public key entry for DKIM in DNS, which, judging by your text you didn't.

Answer 2

The topic of mailings is very relevant, but also very confusing, especially with DKIM + phpmailer, and in order to understand it, I spent more than one hour reading the manuals.
The link above leads to my blog, and for me the easiest solution was to ask me for help. If you have free time, I would definitely suggest in which direction you need to move on;)