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  3. Email Setup

Configure Your Mailbox in Apollo

Article author
Apollo Team
Updated

Overview

After you link a mailbox, configure it in Apollo to fine-tune how you send and protect deliverability. Add an Apollo email signature, set sending limits, and include an unsubscribe link to keep your outbound compliant and consistent.

To keep your mailbox healthy, use a custom tracking subdomain, send from an authenticated domain, and enable open tracking only when running deliverability experiments. Monitor mailbox health and deliverability score to catch issues early, and use the troubleshooting section if your mailbox won’t connect, won’t stay synced, or gets removed.

Configure Your Mailbox

After you link your mailbox, configure your preferences:

  1. During mailbox linking, click Check mailbox configuration, or alternatively, navigate to Settings > Mailboxes, then click ... > Configure mailbox beside the mailbox.
  2. Add a signature to the emails you send from your mailbox. Emails sent outside of Apollo from this mailbox won't include your Apollo email signature. Aliases use the signature of the mailbox they're connected to.

Add a signature. 

  1. Set email sending limits to control the number of emails sent from your mailbox. To keep your domain safe, aim to keep your email activity as close to average as possible. If your sending limits are too high, you're more likely to encounter deliverability issues.

Set sending limits. 

  1. Add an unsubscribe link to the emails you send.

Add opt-out link and open tracking. 

Send Strategies

Only enable open tracking if you have a healthy domain reputation, have been actively following email best practices for a while, and know when to activate and deactivate open tracking strategically for campaign experimentation. Deactivate open tracking when you're not running specific experiments.

If you already use SendGrid for transactional or marketing emails, and you don't want to use open tracking, deactivate open tracking on SendGrid as well.

  1. Select a custom tracking subdomain or create a new one. Subdomains help protect your primary domain and improve email delivery rates. Apollo recommends that the subdomain match the domain of your linked mailbox.

Set up a custom tracking subdomain. 

  1. Use an email address with an authenticated domain. This helps verify email senders, which means your emails are more likely to be trusted. Check out Set Up Email Domain Authentication to learn more.

Use domain authentication. 

To ensure that your linked mailbox doesn't encounter sending issues, monitor the mailbox deliverability score, and follow Apollo's recommendations to adjust your settings or email behavior.

 
Edit Configuration

You can edit your mailbox configuration at any time. To do so, click Settings > Mailboxes. Then, click ... > Check mailbox health.

Check mailbox health button highlighted 

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Troubleshoot Mailbox Configuration

Troubleshoot Mailbox Configuration

Why doesn't my custom mailbox stay synced to Apollo? Why was my mailbox removed? How do I resolve a Failed 120 HTTP 422 error on Microsoft Outlook?

Why doesn't my custom mailbox stay synced to Apollo?

If your custom mailbox frequently disconnects from Apollo, it could be due to authentication errors or server restrictions. Ensure that your email server's IMAP and SMTP settings are correctly configured and that your credentials are up to date. If issues continue, consult your email provider or reach out to Apollo support.

Why was my mailbox removed?

There could be a few different culprits. Try the following to resolve the issue:

Check your linked mailbox settings

If Apollo can't authenticate your email account's login credentials, Apollo removes the mailbox. Authentication failure can happen for a few reasons:

  • You change your email account password
  • You set up two-factor authentication for the first time
  • You deny Apollo access to your email account
  • You make changes to your email account security settings that prevent Apollo from authenticating your mailbox

If Apollo detects changes to the email linked to the mailbox, Apollo notifies you through email that you have invalid credentials.

 
Microsoft Exchange

If you two-factor authentication enabled for a Microsoft Exchange email account, you must generate an app password from Microsoft. Check out Microsoft Support for instructions. You must use the app password to authenticate your mailbox with Apollo. Nylas doesn't directly support two-factor authentication.

Relink your mailbox

If your mailbox is removed, relink it by following these steps.

Back to Troubleshooting

How do I resolve a Failed 120 HTTP 422 error on Microsoft Outlook?

With Microsoft Outlook, you may receive a Message delivery submission failed 120 / HTTP 422 error. There are a few different tactics that you can use to diagnose and troubleshoot this error:

Check your email and server configuration

Messages sent in Apollo are routed through Nylas API. If you receive the Failed 120 / HTTP 422 error for any of your sent messages, confirm the following:

  • Is your send-from email address the same as the address synced within Apollo?
    • For example, if you've connected the account user@ymail.com, but you set the from email as new_user@ymail.com when sending through Nylas API, you might receive the 120 / 422 error returned from Microsoft. You may also see an exception like Exception message: MapiExceptionSendAsDenied: Unable to submit message in Microsoft Exchange logs.
  • Has your Microsoft Exchange server quarantined the syncing devices Nylas uses to sync?
  • Check to see whether Outlook has any of the following potential issues:
    • The Mobile > Mobile Device Access lists no quarantined devices.
    • You've enabled mobile device provisioning.
    • There are no conflicting device access rules as defined by the Suggested Office 365 Settings on Nylas Support.

Check out Nylas Support for additional troubleshooting help.

Allowlist Nylas IP addresses

If your settings in Outlook all match the expected settings listed above, it's possible that your mail server has blocked Nylas from sending messages on your behalf. If your email account settings have an allowlist / whitelist security feature, you should add the Nylas IP addresses to your allowlist.

Apollo recommends that you reach out to your company's email administrator to confirm whether you can add IPs to an allowlist. Then, refer to the instructions on the AWS Public IP Address Ranges Now Available in JSON Form. You should allowlist all IP ranges designated as "us-west-2" in the JSON file. This file is available on the Amazon AWS site of IPs.

 
SendGrid? See Here

If you're using SendGrid with Apollo, the troubleshooting steps listed above don't apply. Check out Configure Your SendGrid Account instead.

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Next Steps

With your mailbox configured, follow these next steps to set yourself up for success:

Use the Deliverability Suite If you're an admin, use the deliverability suite to spot mailbox issues across your team. Fix bottlenecks, and keep your org's emails hitting inboxes instead of spam.
Set Up Domain Authentication Domain authentication is critical to ensuring email deliverability. If you don't properly configure domain name system (DNS) records like SPF, DKIM, and DMARC, your emails are at risk of being labeled as spam. After you link your mailbox to Apollo, follow the instructions in this guide to set up your DNS records.
Configure an Unsubscribe Link To stay compliant and respectful of your audience, every email in Apollo should include an unsubscribe link. Apollo makes it easy to add one in your signature or email templates, helping reduce spam complaints and keeping your domain reputation healthy.
Join the Apollo Community Ask questions, swap tips, and connect with other Apollo users to grow your knowledge and solve problems faster together!

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