Guide · Email and Slack

    How to forward emails to a Slack channel automatically

    Four ways, from free to fully automatic, with the steps for each and what each one can't do. Pick the simplest one that fits.

    The ClearMakes Inbox team · Last updated 29 September 2026

    What does forwarding email to Slack mean?

    Forwarding email to Slack means new emails appear in a Slack channel automatically, so the team sees them without anyone copying them across. Slack gives paid workspaces an email address per channel; Gmail filters and Outlook rules can send mail there. Automation tools, such as ClearMakes Inbox, can also choose which emails to post and summarise them.

    Way 1: get the channel's email address in Slack

    On a paid Slack plan, every channel or direct message can have its own email address. Anything sent to it appears in the conversation.

    1. Open the channel

      Click the channel name in the header.
    2. Open the Automations tab

      Choose “Send emails to this channel”, then “Get email address”.
    3. Copy the address

      You will paste it into Gmail or Outlook in Way 2 or 3.

    Slack says channel addresses need a paid subscription, and HIPAA-compliant Enterprise organisations can't send email to Slack. Free workspaces can use Slack's Gmail or Outlook add-on (one email at a time) or a Slackbot forwarding address (into your own Slackbot messages, not a channel). Source: Slack Help, Send emails to Slack, checked 29 September 2026.

    Way 2: a Gmail filter that forwards to Slack

    Gmail can forward every email, or only the ones a filter matches, to the Slack address. You add the address once, confirm it, and then build the filter.

    1. Add the Slack address as a forwarding address

      Gmail Settings, “Forwarding and POP/IMAP”, then “Add a forwarding address”.
    2. Confirm it

      Gmail sends a verification message to the new address, so it arrives in your Slack channel. Open it there and follow the link.
    3. Forward only what matters

      Leave full forwarding off. Search for the emails you want (for example from:yourclient.com), choose “Create filter”, tick “Forward it” and pick the Slack address.

    Google notes that automatic forwarding sends every message unless you use a filter. Source: Gmail Help, automatically forward messages, checked 29 September 2026.

    Way 3: an Outlook rule that forwards to Slack

    An Outlook rule can forward matching emails to the Slack address, but many Microsoft 365 organisations block automatic forwarding to outside addresses. Test it with one email before you rely on it.

    • Create a rule: when a message arrives that matches your conditions, forward it to the Slack address.
    • If the test bounces with 5.7.520 “Access denied”, your organisation blocks external forwarding. Microsoft turned it off by default for new organisations in 2021.
    • Ask your admin to allow it for this one address, or use a connected app instead (Way 4).

    Source: Microsoft Learn, control external email forwarding, checked 29 September 2026.

    Way 4: a workflow that posts to Slack (works on free Slack)

    An automation tool reads the mailbox through a connected app and posts to Slack itself, so it needs no channel address and no forwarding rule. It can also choose the emails and write a short summary.

    In ClearMakes Inbox

    “When a customer emails support@, post the sender, subject and a two-line summary to #support in Slack.”

    1. When an email arrives in Gmail
    2. Check it is from a customer
    3. Summarise it
    4. Post to #support in Slack

    With ClearMakes Inbox

    1. Connect Gmail (or Outlook) and Slack

      In the Apps page of ClearMakes Inbox. The free plan allows 3 apps.
    2. Type the sentence

      Describe which emails, which channel and what the post should say.
    3. Check the steps and switch it on

      Inbox asks at most one question. Every run is then listed with its steps.

    Other tools do this too. Zapier's free plan runs two-step Zaps and checks for new email every 15 minutes; its Professional plan is $29.99 a month for 750 tasks. ClearMakes Inbox's free plan includes 100 runs a month, and Starter is $29 a month for 5,000 runs. Sources: Zapier pricing (checked 29 September 2026) and ClearMakes Inbox pricing.

    Which way should you pick?

    Use the free ways when a plain copy is enough. Use a workflow when you need to choose, summarise or route emails, or when Slack is on the free plan.

    Ways to forward email to Slack compared
    WaySlack planChooses emailsSummaryMain catch
    Slack channel address + Gmail filterPaidYes, with a filterNoWhole email copied
    Slack channel address + Outlook rulePaidYes, with a ruleNoOften blocked in Microsoft 365 (5.7.520)
    Slack Gmail/Outlook add-onAnyYou pick each emailNoManual, one email at a time
    Workflow (ClearMakes Inbox, Zapier, Make)AnyYesYes, with a stepAnother tool to connect and pay for above its free plan

    Checklist before you switch anything on

    • Pick one channel per kind of email, so people know where to look.
    • Decide who replies: forwarding to Slack does not answer the customer.
    • Keep private emails out: forward by sender or subject, never everything.
    • Send a test email and read what arrives in Slack.

    Questions people ask

    Can I forward emails to a Slack channel on the free Slack plan?

    Not with a channel email address: Slack keeps those for paid plans. On the free plan you can send single emails with Slack's Gmail or Outlook add-on, use a Slackbot forwarding address for your own messages, or use an automation tool that posts through a connected Slack app.

    Why do my forwarded Outlook emails bounce?

    Many Microsoft 365 organisations block automatic forwarding to outside addresses, and a Slack address counts as outside. The sender gets a 5.7.520 “Access denied” bounce. Your admin can allow it, or you can use a workflow that posts to Slack instead.

    How do I forward only some emails?

    In Gmail, create a filter with your search (for example from:customer.com) and choose “Forward it”. In Outlook, use a rule. With a workflow, describe which emails count in plain words, such as “only emails from customers”.

    Can Slack show a summary instead of the whole email?

    Forwarding copies the whole email. To post a short summary, the sender and a link instead, you need an automation step that writes the post, for example a ClearMakes Inbox workflow.

    Want it to choose and summarise for you?

    Connect your mailbox and Slack, type one sentence, and check the steps.

    Free plan: 3 apps, 2 new workflows and 100 runs a month.