Just one word: CONTACTS
Paramount option to have a usable service 4everyone

Contacts and Calendar options would be great. Currently using my own Nextcloud to avoid google as much as possible.

Contacts sync please so we can ditch other providers! (calendar is more for business but contacts is for everyone, have to be able to call my wife :)

If they will sync it with mobile then it will create a problem. SO maybe different apps would be good idea. I also need this feature.

What? does this even mea?

I don’t think this would be a good idea. It would defeat ProtonMail purpose, which is SECURITY & PRIVACY. A workaround for this, would be a ProtonMail Calendar and Contacts Add Ons

This feature would be a nice alternative to the Google stuff, i miss a trusted secured calendar app. Proton could be a leader in trusted app. I would love to see a partnership with eelo.io

+1 for calendar and contacts can be edited on the phone

Calendar would be amazing! I'd prioritize that over notes or chat. It was hard enough to get people on Signal — and the secure chat app market is becoming oversaturated — so I don't understand the requests for sms/mms.

Absolutely no! Why!? Because it slows down server and will cause a lot of security threats! Where are reason for sync? Your unsecured stuff not going to be more secured or priority, because it's still on other unsecured devices, somebody's memory!

I would use all 10 of my votes for this if I could. I support most of the reasons others have explained - security, convenience of having everything in one place. Calendar, TASK LISTS, Contacts and Notes would be amazing. If they could work together even better: having the option to have a task deadline appear on the calendar or if you have an appointment to call a contact it would be great to have the contact information within the expanded appointment. Total integration would be so sexy.

We need a calendar because Google does not respect our privacy: it has our contacts and reads our activities to send us publicity.

I would love to either have this available to use via the phones native contacts/calendar app...but to be honest would prefer ProtonMail just add Calendar and Contacts to their app so I can keep a everything synced to my phone yet still encrypted.

It would be very nice to have this feature and dont neet to use Google or Facebook sevices

Allow this to be optional but also allow sync to private cloud systems like nextcloud via carddav or cladav.

go use some other of the most all email that offers that. I Pay For protonmail, partly because it doesn't.

There is a product - Nuvolect SecureSuite that is an encrypted alternative to the "contacts" on your phone. From the SecureSuite you can send mail through protonmail on your phone, and you can send mail TO A GROUP through protonmail on your phone. The nice thing about a dedicated contact manager is that it also can be used to place calls and send messages through 'Signal' or your default SMS. It provides an alternative to having your contacts available for all of your apps to see.
It does have a calendar, but in the current version it is a little lame. I am not seeing notifications from events, but it could be a setup issue.

CardDAV is a must! encrypted contacts? come on ... that is to much, add the option: you want contacts sync with your iPhone, than no encryption, but add the option!
Also calendar would be nice to close the gap and have everything gmail has as basic and free.

If you sync with your phone then you open up for Google to certainly invade your privacy. After all Android is their baby. Everyone will need an Iphone in order to remain safe.

Love it....