The 8 Best Unified Inbox Apps to Combine Email, Slack & Teams (2026)

Nolario pulls Gmail, Outlook, Slack, Microsoft Teams and Google Calendar into one feed, scores every item for importance, and ranks the feed so the important thing is at the top, whichever channel it came from. It drafts replies in your own voice from what you actually send. It ranks, it never answers for you.

Nolario is our product, so weigh this pick accordingly. We rank it first because it is the only app in this list that merges all three channels into one list instead of tabs, and the only one that orders that list by what needs you. What it does not do: it is not available today, since access is by waitlist and the product opens to waitlist members between May and August 2027; it runs on the desktop only; and it has no shared queue or assignment for a team. See the integrations and pricing pages.

Wavebox is a desktop browser built for work apps. You group Gmail, Outlook, Slack and Microsoft Teams in a sidebar, stay signed in to several accounts of the same app at once, and search across them with its unified search. Unread badges show which app has something new, and split screen puts two apps side by side.

It runs on Mac, Windows and Linux and takes Chrome Web Store extensions. The free Basic plan is small, 2 groups with 2 apps in each, so most people who stay end up on Pro, which starts with a 7 day trial and no card.

The limit is the one every work browser shares: Slack still looks like Slack and Gmail like Gmail. You see which tab has something unread, not which message matters.

Shift puts your mail, chat and work apps in one window and groups them into Spaces. Each Slack workspace gets its own entry in the sidebar, and you can stay signed in to several Microsoft Teams accounts or tenants at once, which is what consultants and people who work for more than one company tend to need.

The free plan allows 5 Spaces with 10 apps in each and limited use of Shift's AI. Advanced costs $199.99 a year, paying monthly costs $40 more over a year, and removes the Space and app limits. Check that the free plan covers every app you need before you rely on it.

Like Wavebox, Shift merges the window, not the messages. It is a fast way to stop hunting for tabs; it does not tell you which of the apps needs you first.

Rambox brings Slack, Microsoft Teams, email and more than 700 other web apps into one interface. The free Basic plan has unlimited apps with up to 2 instances of each, plus notifications and a focus mode, which is enough to run two Gmail accounts, Slack and Teams side by side.

Pro adds workspaces, multi-login and unlimited instances for $7 a month or $70 a year, and every new account starts with a 30 day Pro trial without a card. A Teams plan costs $14 per user a month from 5 users. Rambox runs on Windows, macOS and Linux.

It gathers apps rather than messages: each app keeps its own notifications, and deciding what matters stays with you.

Front merges email and other channels into one shared inbox that a team works together. On the Professional plan and above it takes Slack as a channel, so you can respond and react to messages from public and private Slack channels in the same queue as your email.

The Starter plan, $25 per seat a month for up to 10 seats with a 14 day trial, supports a single channel type: email, Front Chat or SMS. Combining email with Slack therefore means Professional at $65 per seat a month. Microsoft Teams does not appear on Front's pricing page.

It is built and priced for a team, so for one founder it is a lot of tool for the job. If a shared queue is what you need, our guide to shared inbox software goes deeper.

Mailbird merges your email accounts into one inbox and docks other apps in a sidebar, so Slack and WhatsApp open in a panel next to your mail instead of in another window. It runs on Windows and on macOS Ventura or later.

The free plan covers a single account and no app integrations, so the unified inbox and the sidebar apps need Premium: $4.03 per user a month billed yearly at the time of writing, or $99.75 once. There is no trial, but there is a 14 day money-back guarantee. Microsoft Teams is not listed on the Mailbird pages we checked.

Missive merges Gmail, Outlook and IMAP accounts with SMS through Twilio, WhatsApp, Messenger and Instagram, so a small team can answer every customer conversation from one list. Each user can connect up to 10 personal and 5 shared accounts.

Plans cost $14, $24 and $36 per user a month, with 20% off when billed yearly, and there is a 30 day trial of the Productive plan without a card, but no free plan. Slack and Microsoft Teams are not among the channels its pricing page lists, so it unifies everything except the chat your team runs on.

Spark's free plan already covers the core of a unified inbox for email: unlimited email accounts, the Smart Inbox, smart notifications and a calendar, on iOS, Mac, Windows and Android.

Plus, at $10 per user a month, and Pro, at $20, add more, including a Microsoft Teams integration in the calendar for meetings. Slack does not appear on Spark's pricing page and Teams shows up only for meetings, so as a unified inbox it covers email only. If email is the whole problem, it is the best free answer here.