Some of registration fail to register gotowebinar via pardot signups

[takarabio]

Gotowebinar is not registering signups and sending registrants confirmation emails. When i log into my account, under my webianrs, it shows only some of registrants. The signups are coming through a pardot form.   only 3 are registered out of 8, and even 3 are success to register, they didn't get the reistrants confirmation emails.  

Why 5 couldn't register for Gotowebinar even though they successed to register pardot?  Those 5 did same process with other 3 who have successed regiser for Gotowebinar.  

Plus, whey even 3 didn't get the confirmation emails even though I set up "SEND" for "confirmation email to resigsrants" ?

[AshC]

@takarabio  I'm sorry we cannot answer why Pardot is not transferring each registrant to GoToWebinar, as the communication breakdown may be on their end. 

With regards to the part we do control -- email confirmations sent by GoToWebinar, it's possible those participants returned our initial communication attempt.  After this happens they end up on a 'blocked' list of our own so we don't antagonize their email account or provider group.  Either you or the affected Attendee themselves may contact Customer Support by phone in order to check this scenario and have the block removed.