Fix mail app sign-in errors
Proton Mail IMAP for Third-Party Clients: Why You Can't Find It
Looking for Proton Mail IMAP settings or an app password for a third-party client? They don't exist for hosted apps - here's why, and the real fix.
Outlook App Password Not Working? Here's Why (and the Fix)
Outlook.com app passwords stopped working in outside mail apps on September 16, 2024. Here's what changed for Outlook.com and Microsoft 365, and the fix.
"IMAP Basic Authentication Is Disabled" on Outlook - What It Means
IMAP Basic Auth disabled error on Outlook.com or Microsoft 365? Microsoft switched it off (2024 for Outlook.com, 2022 for Microsoft 365). Here's the fix.
How to Connect Outlook to a Third-Party Email Client (2026 Update)
Password-based Outlook setup no longer works in outside mail apps. Connecting Outlook.com or Microsoft 365 to a third-party client now takes Microsoft sign-in.
What Is Microsoft Modern Authentication, and Why Does My Client Need It?
Modern Authentication (OAuth 2.0) is how third-party email clients sign in to Outlook.com and Microsoft 365 now that password sign-in is off. Here's why.
Outlook SMTP Authentication Failed? Here's the Real Cause
SMTP auth failed sending from Outlook.com or Microsoft 365 in a third-party client? Here's what Microsoft changed, what's still coming in 2026, and the fix.
Gmail App Password Not Working? Here's How to Fix It
Gmail rejects your password or app password in a mail app? Why Google blocks it, how to make a fresh app password, and the fastest way to connect.
Yahoo Mail Won't Connect in Your Mail App? Fix It With an App Password
Yahoo Mail says your password is wrong in a mail app? Outside apps need a Yahoo app password. How to make one and connect it in a few minutes.
iCloud Mail Won't Connect? Fix the App-Specific Password Error
iCloud Mail refusing your Apple ID password in a mail app? You need an app-specific password. How to make one, why it stops working, and how to connect.
Free tools
Curo vs. the alternatives
Superhuman alternative
Superhuman is fast but you still triage every email yourself and it's single-focus on spee
HEY alternative
HEY reinvents email rules manually (Imbox/screening); Curo automates prioritization with A
Shortwave alternative
Shortwave brings AI to Gmail only; Curo works across every mailbox (not just Gmail), is en
Spark alternative
Spark offers smart inbox + team features; Curo goes further with AI triage that surfaces o
Missive alternative
Missive is built for team shared inboxes; Curo is the AI chief of staff for the individual
Notion Mail alternative
Notion Mail brings automation to Gmail; Curo unifies ALL accounts, adds encryption, and le
SaneBox alternative
SaneBox filters with folders on top of your existing client; Curo is a full AI inbox that
Gmail alternative
Gmail's built-in AI is generic; Curo reads across Gmail AND your other accounts, surfaces
Outlook alternative
Microsoft has been retiring Basic Auth / app passwords: personal Outlook.com, Hotmail, Liv
Proton Mail alternative
Be scrupulously honest: Proton offers no IMAP or API to third parties by architecture and
Thunderbird alternative
Thunderbird is a free, open source desktop app you tune by hand with folders and filters;
Mailbird alternative
Mailbird is a polished desktop client with a unified inbox; Curo adds AI triage and voice-
Canary Mail alternative
Canary Mail is a privacy focused client with PGP support; Curo shares the privacy focus an
Edison Mail alternative
Edison Mail is a mobile first inbox with clean up tools; Curo reads everything and brings
Yahoo Mail alternative
Yahoo Mail still supports IMAP with an app password (2-step verification required); Curo c
iCloud Mail alternative
iCloud Mail works well inside Apple's ecosystem via an app-specific password, but has no A
AOL Mail alternative
AOL Mail still supports IMAP with an app password but offers no meaningful AI triage or cr
Zoho Mail alternative
Zoho Mail is a solid business inbox with its own light automation, but triage stays manual
Fastmail alternative
Fastmail is a fast, privacy-respecting IMAP host with strong search and rules, but rules a
GMX Mail alternative
GMX Mail supports IMAP with an app password and offers basic spam filtering, but no AI pri
Mail.com alternative
Mail.com supports IMAP with an app password but has no AI triage layer; Curo connects it,
Yandex Mail alternative
Yandex Mail supports IMAP with an app password and has its own spam filtering, but no pers
Hostinger Email alternative
Hostinger Email (Titan) is solid custom-domain IMAP hosting for a business, but has no AI
Best email by profession
Best email for founders
founders get buried in investor, customer, hiring and vendor email across multiple account
Best email for executives
executives need a chief of staff for their inbox — only the truly important surfaced, the
Best email for lawyers
lawyers juggle client, court and matter email where missing one message has real consequen
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agents live in email with leads, lenders, clients and listings, and a slow reply loses the
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consultants manage many clients in parallel and need every thread prioritized and replied
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sales reps must reply fast to the right prospects across inboxes or the lead goes cold
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agency owners drown in client, prospect and team email across brands and accounts
Best email for recruiters
recruiters run hundreds of candidate and client threads where speed and personalization wi
Best email for busy professionals
busy professionals get hundreds of emails a day across work and personal accounts and want
How Curo works
AI email triage
what AI email triage is and how Curo surfaces only what needs you
inbox zero with AI
reaching and staying at inbox zero by letting AI prioritize and handle the rest
AI email assistant
an AI assistant that reads, prioritizes and drafts your email in your voice
unified inbox for multiple accounts
managing all your email accounts in one secure place with AI
AI reply drafts in your voice
AI that drafts replies that actually sound like you
encrypted email for business
private, end-to-end encrypted email with AI on top, for business
email that sorts itself
an inbox that prioritizes and organizes itself automatically with AI
how to clear your inbox in 15 minutes a day
a practical daily routine for getting through a full inbox, and where Curo does the sortin
how to write email replies faster
five habits for faster replies that still sound like you, and how Curo drafts the first ve