watchMX/invalidについて、ここに記述してください。

isj.co.jp 

;; ANSWER SECTION:
isj.co.jp.              86400   IN      MX      0 ms43003691.msv1.invalid.
isj.co.jp.              86400   IN      MX      0 isj.co.jp.

jfps.or.jp

ripple.gr.jp 

ripple.gr.jp.           86400   IN      MX      0 ripple.gr.jp.
ripple.gr.jp.           86400   IN      MX      999 ms80980619.msv1.invalid.

cpnet.co.jp

-- ToshinoriMaeno 2019-04-21 07:10:22

https://business.forums.bt.com/t5/Archive/Invalid-TLD-in-MX-Record/td-p/50218

The invalid MX record has most likely been introduced, because someone has added a new (and bogus) MX record to the domain, in order to prove domain ownership during the Microsoft Office365 migration process.

Although there is the option to add a "TXT" record (which should not adversely affect any services), it appears that many people are adding bogus "MX" records instead (which is likely to cause problems with mail delivery). Either way, once the domain ownership verification process has been completed, the temporary DNS records should be removed (especially if it's a bogus/invalid MX record).