Opensolr Mail

Content rating
Everyone
0+
Downloads
Content rating
Everyone
Users Interact
Learn more
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image

About this app

Opensolr Mail is an open source mail app for Fastmail. All your Fastmail accounts in one unified inbox, conversations in threads, push notifications you can act on, Fastmail Notes, your Fastmail calendars in the phone's calendar and one list of contacts. A Fastmail account is all it needs.

ONE INBOX FOR EVERY ACCOUNT
• All Inboxes, Drafts, Sent, Archive, Junk, Trash and Flagged across every Fastmail account, plus each account's own folders.
• Conversations grouped in threads; the list grouped by day, month, sender, company or account.
• Swipe left to delete, right to flag. Long press to select conversations for bulk actions.
• Mark all as read on any view. Long press Trash or Junk to empty it.

NATIVE FASTMAIL SIGN-IN
Your Fastmail password and two-factor code are typed on Fastmail's own page, in the phone's browser. The app never sees them and needs no IMAP settings and no app password: it talks JMAP, with OAuth 2.0 and PKCE.

PUSH YOU CAN ACT ON
New mail arrives at once. Each notification has three actions: Mark as read, Delete, and Reply all, typed right in the notification.

NOTES AND CALENDARS
• Fastmail Notes, read and written from the app.
• Each account's Fastmail calendars sync both ways into Android's calendar, so they show up in any calendar app.

CONTACTS
Your Fastmail address books and, only if you allow it, the phone's contacts, merged into one card per person, with a search box and Compose on each card. The same people are suggested as you type in To, Cc and Bcc. Nothing is ever edited or deleted.

SEARCH
• Fastmail search: by words, newest first, on Fastmail's own servers, with nothing else to connect.
• Opensolr search, with an Opensolr account: every message you ever received, with the text inside its attachments, searchable by words and by meaning, an AI answer drawn from your own mail, filters (from, to, company, account, folder, year, attachment type, dates, unread, flagged, answered) and grouping.

YOUR DATA
• No analytics, no ads, no tracking.
• Your mail stays between Fastmail, your phone and, only if you connect one, your own Opensolr Index.
• Sign-in tokens are stored encrypted with an Android Keystore key and are excluded from phone backups.

Seven languages: English, Deutsch, Français, Español, Română, 日本語, 中文.

Requires Android 8.0 or newer and a Fastmail account.
Every Fastmail account in one inbox, and all of your mail found in a second.
Updated on
Oct 7, 2026
Featured stories

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
    Learn more about how developers declare sharing
  • This app may collect these data types
    Personal info, Messages, and Device or other IDs
  • Data is encrypted in transit
  • You can request that data be deleted
Content rating
Everyone
Users Interact
Learn more

App support

Phone number
+40737883303
About the developer
OPENSOLR S.R.L.
cip@opensolr.com
STR. ALEXANDRU VAIDA VOEVOD NR. 14 AP. 1 400601 CLUJ-NAPOCA Romania
+40 737 883 303