Connect it in two minutes
Add the Nilyo app in ChatGPT, or enable developer mode and add a connector with the URL https://nilyo.com/mcp and OAuth. Then connect the mailbox: give the address and the password and the servers are detected from the address — you normally never type a host or a port. Only if detection fails are you asked for them, and the authoritative place to copy them from is the account settings of the mail client you already use.
An app password is mandatory, not a fallback
On most hosts an application password is what you fall back to when two-factor authentication blocks the account password. On Fastmail it is the only way: IMAP access always uses an app password created in the security settings, and you can scope it to mail only. That is a genuinely good design — the credential you hand over cannot change your account settings, and revoking it cuts exactly one connection without touching anything else.
What it is actually good for here
Fastmail users tend to have a heavily filtered mailbox already, so the gain is not sorting — it is asking questions across what the filters put away: find the thread where the date was agreed, summarize what this person has asked over six months, tell me which threads are waiting on me across every folder.
“What arrived since yesterday that needs an answer from me?”
“Find the thread where we agreed the delivery date and quote the message.”
Revocation is the part worth appreciating
Because the connection uses a dedicated app password, you have a clean off switch that does not involve changing your account password or disconnecting anything else. Disconnecting the mailbox on our side does the same thing from the other direction.
When it stops working
Two causes cover nearly everything. The password is refused after it worked: an application password was revoked, or the mailbox password was changed — generate or update it and reconnect the same mailbox rather than adding a second one. The agent suddenly sees nothing: the session expired, and the card in the answer carries the reconnection link. A mailbox that moved host is reconnected with the new servers, not re-added, so anything referring to it keeps working.
Common questions
Can ChatGPT read my Fastmail account?
Yes, over IMAP, using an app password generated in Fastmail’s security settings — the account password is never accepted for IMAP.
Do I need to type the servers?
No, they are detected from the address. You are only asked if detection fails.
How do I revoke access?
Delete the app password in Fastmail, or disconnect the mailbox on the Nilyo side. Either cuts the connection without touching your account password.
How Email works with Nilyo
Connection. Gmail and Microsoft 365/Outlook through their official sign-in (the “Unipile” name appears on the consent screen: Unipile SAS operates the connection). Any other mailbox through IMAP/SMTP: OVH, Zoho, iCloud, IONOS, Infomaniak, Fastmail, Yahoo, GMX and self-hosted servers.
What your agent can do. Folders and labels, listing and searching messages, reading with attachments, drafts, sending and true replies, moving and labelling, contacts on Gmail and Microsoft.
Pacing and safety. No local budget; provider limits apply. IMAP mailboxes are read live, so listings are paged (50 messages max per page).
- “How many emails today” uses the folder counts of the mailbox; “today” is a date filter, never a guess.
- On IMAP a message id changes after a move; Nilyo returns the new id so the agent keeps working on the right message.
All Email guides
Related guides
Give Nilyo to your agent.
Paste one setup link. Your agent can guide OAuth, account connection and the first useful action.