When looking internally, it seems that there is a global bounce on this email address (I have hidden the email address on your post for security and confidentiality reasons): This is a hard bounce for a permanent reason across three or more HubSpot accounts. Permanent bounces include unknown user and mailbox full. Global bounces are dropped from future emails across all HubSpot accounts.
When looking internally, it seems that there is a global bounce on this email address (I have hidden the email address on your post for security and confidentiality reasons): This is a hard bounce for a permanent reason across three or more HubSpot accounts. Permanent bounces include unknown user and mailbox full. Global bounces are dropped from future emails across all HubSpot accounts.