Less granularity of features / too many upsell cards
Been using Proton Plus for a while now. It's a great service. I also pay for Simplelogin Premium subscription.
With that said, Mail Plus does not feel like it's a premium (or even a paid) service because literally every time I go to access settings, there are upsell cards for Unlimited being 'Recommended' - along with the permanent 'Get Unlimited' on my mailbox screen
As a paying customer, I don't think it is reasonable to be constantly badgered to pay more.
Related to this, you're too stingy with Mail Plus. Recently I:
1) Wanted to give ProtonVPN a proper test drive. You only offer free servers in 2 countries to Mail Plus users, so this was no good to me.
Suggestion: Allow Mail Plus subscribers a single connection to a Standard server in the country they are a registered customer in
2) Basic features require upsell, sometimes to a different plan entirely
Example: I would like to use SMTP to send notifications from a network device, but this is only available on business, despite there being many free tools to do this
Suggestion: Allow low-cap usage of SMTP on Mail Pro
The combination of constant upsell notifications plus the inability to test anything without committing, ironically, makes me less likely to remain a Plus customer in the long run.
Thanks.