Email Deliverability Best Practices

This article gives you tips and tricks to ensure your emails are being seen by your contacts

Soumya Jud avatar
Written by Soumya Jud
Updated over a week ago

As a recruiter, whether working for an agency or in-house, ensuring your emails get seen by your contacts is crucial. There is no perfect solution but utilising a platform like SourceWhale and incorporating the following advice will reduce the risk of emails being flagged as spam.

Understanding Email Deliverability

Email deliverability refers to the likelihood of your email reaching the recipient's inbox without being flagged as spam or being blocked. Factors influencing deliverability include email content, sender reputation, recipient engagement, and compliance with email provider (e.g. Microsoft, Google, Yahoo etc.) policies.

Recommended Email Set Up

Successful email deliverability begins with proper email technical setup:

  • Confirm SPF, DKIM, and DMARC are configured and passing authentication checks. Correct setup can be checked using SourceWhale’s deliverability tester.

  • Set up a Custom Tracking domain, ensuring your email links are associated with your domain, reducing the likelihood of being marked as spam.

  • Use tools like Google Postmaster to monitor your domain/IP reputation, essential for understanding your email performance. Note that Google Postmaster is only specific to your sending behaviour to Gmail based emails and requires a certain volume of emails being sent specifically to the to show data.

Recommended SourceWhale Email Settings

SourceWhale offers various ways to help maintain good deliverability.

At the user level:

  • Set an email delay of at least 120 seconds to prevent appearing as automated bulk sends.

  • Set a daily send limit of around 150 emails per day, with larger teams reducing this limit further

  • Check your content with Content Coach to better personalize your emails and help you eliminate spam phrases.

  • Make sure you are personalizing messages that you send (a rough minimum of 10% of the content in the email).

At the team admin level:

Best Practices for Recruiters

We recommend the following to maximize your chances of deliverability:

  • Maintain a consistent email volume; sudden spikes can trigger spam filters.

  • Ensure no broken images or links in your emails.

  • Keep email sizes under 100KB and attachments below 10MB.

  • Maintain low bounce (<5%) and complaint rates (<0.1%).

  • Promptly remove bounced and unsubscribe addresses from future sends - SourceWhale will automatically detect unsubscribe requests and add these users to the unsubscribes list.

Sending Bulk Emails to Google and Yahoo Domains

Beginning in February 2024, Google and Yahoo are set to gradually implement new limitations on the sending of high-volume, bulk emails to their respective domains. The definition of a bulk sender is emailing more than 5000 emails a day to Google and Yahoo domains.

This applies at the domain level rather than platform level - for example, all emails sent from a domain (e.g. '') will be counted regardless of whether they are sent manually, utilising SourceWhale or using a marketing automation platform.

Please note, Google's current guidance is that the new sender guidelines (linked below) only apply when sending emails to personal Gmail accounts, not Google Workspace accounts (e.g. any domain which utilises Google as their email provider but ends in

Taking into account these changes do not include Microsoft email provider customers and Gmail corporate email customers, it is unlikely you are emailing over 5000 emails a day to personal Gmail and Yahoo domains consistently and so will not be classified as a ‘bulk sender’ but if you do, non-compliance with these new rules could lead to the blocking of your emails to Google and Yahoo domains temporarily. Consequently, users with email addresses ending in,, or might not receive your messages.

Google and Yahoo have both confirmed they will be gradually implementing these changes.

To minimize any risk, we recommend the following:

  • Authenticate with SPF/DKIM/DMARC.

  • Keep spam complaint rates below 0.3%; ideal is under 0.1%.

  • Include opt-out links.

  • Limit daily sends to 150, with adjustments for larger teams.

  • Set an email send delay of 180 seconds.

  • Restrict domain sends to '5' per day.

  • Personalize your emails; aim for at least 25% customization.

  • Remove unresponsive recipients after 9 months.

  • Split out high-volume email sending on to a separate domain (ideally managed under a different email provider account) to decrease the risk of being classified as a bulk sender. For example marketing or ‘mail blast’ emails onto a different domain such ‘’ vs your usual ‘’ .

For further information on bulk email restrictions, refer to:

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