All docs sent for signature are going to recipient's junk mail folder

ALL of the documents that we are sending now are being marked as junk mail OR spam no matter the recipient's email provider: @8395988, @10215394, @AOL, @yahoo, etc. We use this platform to send onboarding documents to new hires and it presents an unprofessional appearance if we have to tell them to check their junk mail folder to find correspondence from us. We also should not have to email them in advance to tell them to add this email to their safe sender list so that they will receive it...although we've tried that as well and it is still routing messages to junk/spam folders. We have changed the sender name (under My Profile), but the email echosign@echosign.com that is the sending email appears to be the issue. Need your help urgently to get this resolved.
Thanks,
Stacy