Office 365 Migration

I've just migrated our companies 150+ users from on premises Exchange 2010 to Office 365. I was responsible for managing and executing the migration. We have had to re-engineer our LOB Applications that generate business email to go through a new Email Gateway Application that I developed. On the whole the migration went to plan apart from Outlook 2010/outlook 2013 where port 443 was getting blocked by our Kaspersky anti-virus software. Just need to sort out Retention Policies, Password expiry and Email delegation. I need to address a few points with: Email Delegation Retention Policies Password Expiry