Contacts

• —Built from the senders and recipients of your own threads, ranked by how often and how recently you write to them.
• —You do not have to maintain an address book for this. The ranking is built from your threads on its own. There is one if you want it, under Contacts in the sidebar, and anything you save there is offered ahead of the thread-derived names rather than mixed in with them.
• —The book belongs to the workspace rather than to one person, so a contact anybody saves is the contact everybody sees, and the API and the MCP server read and write the same rows. Contacts can also be put into audiences, which are named lists you define beside the built-in one that holds everybody, and one email can go to everybody in an audience, a separate copy for each person.
• —Everything the Contacts page does can also be done over the API, the SDK and the MCP server: list everyone seen in mail with their thread counts, show only the blocked, save somebody, delete them, set their photo, block and unblock them, and read the conversations and the activity with one person. Deleting somebody hides the address, so writing to them again does not put them back on the list.
• —A saved contact holds what the address book on a phone holds: phone numbers, other email addresses, postal addresses, websites, company, job title, birthday and notes, each number and address with a label such as Mobile or Work. A contact can also be only a name and a phone number, the way most phones save a plumber or a taxi firm, and those are listed under No email on the Contacts page.
• —The address book syncs both ways with Apple Contacts on an iPhone, iPad or Mac, with Android through DAVx5 and with Thunderbird, over CardDAV. They sign in with one of your addresses and an app password for it, and a contact added, changed or deleted on either side shows on the other. Nothing is taken from a phone until you connect it.
• —A contact also holds custom fields, up to 50 values such as a plan or a signup source, set on the contact page or through the API. Automations can read them and write them.

A saved contact is a full address book entry. Open it on the Contacts page and choose Add details, or Edit details once it has some, to change everything except the address it is saved under.

• —Phone numbers, other email addresses, postal addresses and websites, each with a label such as Mobile, Home or Work. A label made on a phone, such as Assistant, is kept and shown as it is.
• —Company, department, job title, nickname and birthday. A birthday can leave out the year.
• —The name, the notes and the photo are the same ones the contact page shows, so a change in one place shows in the other.
• —New contact, at the top of the Contacts page, adds somebody by hand, with or without an email address. A contact with no email address, such as a plumber saved on a phone with only a number, is listed under No email.

Apple Contacts on an iPhone, iPad or Mac, DAVx5 on Android and Thunderbird sign in to your contacts over CardDAV and keep them in step both ways: a contact added, changed or deleted in the app shows in Nextmail, and the other way round. Sync with your phone, at the top of the Contacts page, shows the same settings.

• —iPhone or iPad: Settings, Contacts, Contacts Accounts, Add Account, Other, Add CardDAV Account, then the server, the address and the app password. Your contacts show in the Contacts app under the new account.
• —Mac: in Contacts, choose Contacts, Add Account, Other Contacts Account, then CardDAV and Manual.
• —Android: install DAVx5, choose Login with URL and user name, enter the server, the address and the app password, and turn on the address book it finds. The contacts then show in the phone’s own Contacts app.
• —Thunderbird: in the Address Book, choose New Address Book, then Add CardDAV Address Book, enter the address as the username and the server as the location, and sign in with the app password.

• —The address book holds the contacts saved in the workspace. The workspace owner sees all of them, and anyone else sees the contacts they added. Addresses only ever seen in mail are not in it.
• —Deleting a contact in the app deletes it in Nextmail too, the way Delete does on the Contacts page, and the other way round.
• —A photo set in Nextmail shows in the app. A photo set in the app is kept with the contact but not shown in Nextmail.
• —Passwords made with a setup link sign in to mail and the calendar but not to your contacts. Revoking an app password signs the app out within about five minutes.
• —Google Contacts and Outlook cannot sign in to another address book. On a phone, your Nextmail contacts show beside theirs in the same Contacts app.

Every contact card is in the REST API under /contacts/cards, in the SDKs and the CLI under contacts, from listCards to deleteCard, and in the MCP tools from listContactCards to deleteContactCard.

• —Reading needs contacts:read and every change needs contacts:write. An API key acts for the workspace owner, so it reads the whole address book.
• —A list you send, such as phones, replaces the whole list. A saved contact keeps its address, so another address goes in emails, and email is only accepted on a card that has none yet.
• —Deleting a card that has an email address deletes the saved contact too.

• —Import contacts on the Contacts page takes a .vcf file of up to 20 MB and turns every card in it into a card here, with its phone numbers, addresses and the rest.
• —Imported contacts join no audience, so a broadcast never reaches somebody because of an import. A card whose address is already saved is left as it is, and a card with no address is matched on its phone number.
• —Remove imported contacts undoes one import: it deletes the cards that import added and leaves the contacts that were saved before it.
• —A live mailbox import brings contacts in the same way: over the same app password for iCloud, Fastmail and Yahoo, over the Microsoft sign-in for Outlook, and from the .vcf files inside a Google Takeout archive for Gmail.

A group gathers people you often write to together, such as a book club. New group in the three dots menu of the Contacts page makes one, and Groups above the list shows them. Phones and computers that sync your contacts keep the groups too, as the group cards Apple Contacts uses.

• —Somebody you add to a group who was not saved yet is saved to your contacts.
• —Find duplicates in the same menu lists the cards that look like the same person: a shared email address, a shared phone number or the same full name. Choose the card to keep, and Merge folds the others into it and keeps every address, number and link.
• —A saved contact merged into another card stays known by its address and in its audiences, but it leaves the address book.
• —Over the API a card takes kind and members to be a group, GET /contacts/cards/duplicates finds duplicates and POST /contacts/cards/{id}/merge merges them.