[v16.4] Automated follow ups on weekdays only and mobile collision detection

We're excited to announce important improvements to our email sequences and mobile app this week.
⛓️ Email sequence follow ups on weekdays only
Previously, it was only possible to schedule automated follow ups based on calendar days. From today, users have the option to only consider weekdays (Monday to Friday) when scheduling future follow up emails in a sequence.
📱 Collision detection on mobile app
Stop multiple users from replying to the same email at the same time, regardless of where they are. Our collision detection now works across our Chrome Extension and mobile app.
⚒️ Other minor fixes and improvements
We have also made some improvements requested by users, including:
Fixed calendar headers not loading in the detail view of emails containing meeting invitations.
Keep unread counts on personal inboxes (previously, those were hidden while Drag was installed).
Freeze top bar while scrolling down in email threads, making it always accessible for users.