ProtonMail operates under the domains protonmail.com, pm.me, and protonmail.ch. With the introduction of protonmail.com, there have been some concerns from users regarding the prudence of introducing the .com top level domain (TLD) since .com is under the control of the US government (more specifically, the .com TLD is managed by VeriSign which is a US company under US jurisdiction).
The primary risk is domain name seizure, which can occur if the US government bypasses the Swiss court system and directly seizes protonmail.com by serving a court order directly to VeriSign. In this case, ProtonMail could lose control of protonmail.com and the US could gain access to emails sent to protonmail.com after the seizure by directing all email sent to protonmail.com to a different server.
This risk exists for any .com domain. At this time, we gauge this risk to be quite low because ProtonMail is operating in compliance with international laws and regulations which protect the right to encrypt data. Encryption is legal, even in the US, and there can be no just cause for seizing our .com domain name.
However, at ProtonMail, our goal is to provide maximum privacy and security under all possible scenarios. For this reason, we continue to provide the added security of the .ch domain, to all users with a paid plan.
We recommend that users concerned about absolute privacy use protonmail.ch.
ProtonMail will continue to use protonmail.com as our default website and webmail portal. We consider this to be low risk because the backend API which needs to be accessed to get user data will continue to be hosted at protonmail.ch.
However, for users who wish to always avoid .com domains, we provide alternative webmail access at app.protonmail.ch. We can also be reached on the .ch version of our official email addresses (for example, firstname.lastname@example.org).
In March 2018, we also introduced a new short domain for email addresses: pm.me. The ME registry belongs to Montenegro, and in terms of safety, we classify it as safer than .com, but not quite as safe as .ch.
If you are looking to change your current address, you can upgrade your account to add more email addresses to your account.