Please see this description which is similar to mine: https://serverfault.com/questions/655250/gmail-bouncing-mail-sent-over-ipv6-ipv4-working
And the answers look interesting. Regards.
- can't send to GSuite mailserver via IPv6 protocol Thomas
- Re: can't send to GSuite mailserver via IPv6 p... Viktor Dukhovni
- Re: can't send to GSuite mailserver via IPv6 p... Philip
- Re: can't send to GSuite mailserver via IP... Erwan David
- Re: can't send to GSuite mailserver vi... Thomas
- Re: can't send to GSuite mailserver vi... Bastian Blank
- Re: can't send to GSuite mailserve... Thomas
- AW: can't send to GSuite mail... ludicree
- Re: can't send to GSuite ... Matus UHLAR - fantomas
