when using "Other mail account" as team address (via forwarding) and option "custom from address" we have huge problem with gmail addresses. Because Gmail ignores reply-to address and send customer's reply to something like support=domainname.com@bf.hubspot-inbox.comwhich is not working. so we lose lot of replies from customers.
Hubspot have a paid option - email authentication, where we can add domain, SPF/DKIM and so on.
question is - will this paid feature help us to resolve this gmail issue or this feature only for marketing emails, not inbox email-2-email?
We are having the same issue, logged it last year with the techincal team and no resolution. Our only way to contact Gmail adresses is to do so directly from Gmail and forwarding any replies from the adresses to Hubspot. It's doing our head in and we are ready to find another CRM platform if Hubspot don't sort it out. Really hope there is a resoltion soon.