Overview
Several factors can influence whether your emails arrive safely in a Contact's inbox. Apollo groups "failed" emails into 3 main categories:
- Apollo has not scheduled or delivered any of your emails.
- Apollo has sent your emails but they have failed to deliver.
- Apollo has not attempted to send your emails.
Refer to the sections below for more information about the possible issues that may prevent your emails from reaching their intended recipients and the appropriate solutions for each issue.
Apollo Hasn't Scheduled or Delivered Any of Your Emails
If you added contacts to a Sequence, but Apollo has not scheduled or delivered any of your emails, there are 3 possible reasons why:
- You have not activated the Sequence.
- You have not activated the steps in the Sequence.
- You need to update the wait time between steps
Refer to the sections below for solutions for these 3 email scheduling and delivery issues.
Activate Sequence
Launch Apollo, click Engage, and then click Sequences.
Make sure that you have enabled the toggle on the left-hand side of the Sequence. If the toggle is blue, the Sequence is active.
Activate the Sequence Steps
Launch Apollo, click Engage, and then click Sequences.
Click the Sequence that you want to review.
Make sure that you have enabled the toggles on the left of each step. If the toggle is blue, the Sequence step is active.
Verify Wait Time Between Steps
Launch Apollo, click Engage, and then click Sequences.
Click the Sequence that you want to review.
Check the wait time between each step. Apollo specifies the timings on the right-hand side of a step. If you scheduled an email to send a few minutes, hours, or days later, Apollo will not send your contacts any emails until this time has passed.
To edit the wait time, click the Additional options (...) button and then click Edit.
Use the Wait for drop-down fields to update the amount of wait time between steps.
Click Save.
Apollo Has Sent Your Emails But They Have Failed to Deliver
If Apollo has sent your emails but they have failed to deliver, there are 3 possible categories of reason:
- The email has bounced
- The email requires manual review
- The emails have not sent
Refer to the sections below for solutions to common email delivery issues.
Bounced Emails
If an email "hard bounces," it means that the email address no longer exists or there is an error in the recipient's information. The ESP returns it to the Apollo delivery system and Apollo updates the email status to Bounced.
For more information about how to resume sending messages to a Bounced Contact in a Sequence, please refer to this article.
Requires Manual Review
If you select a Manual Email step in the Sequence, the email will not send automatically. To send the email, launch Apollo, click Engage, and then click Sequences.
Click the Sequence that you want to review.
Click Tasks.
Then, click the Email icon.
Personalize the email for that specific Contact and then click the Schedule drop-down.
You can choose to either Send Now or Set delivery schedule for later.
Not Sent
Several other reasons may impact the delivery of your emails.
Reason | Explanation | Solution |
---|---|---|
Blocked Contact Stage | When you create a Sequence, you have the option to mark emails as Not Sent when a Contact is in a given Contact Stage. For example: ![]() |
You can change the stage of a specific Contact that you want to send to or you can change the settings in the Sequence so that Apollo no longer blocks emails to any Contacts in that stage. When you have made this change, try sending the email again. |
Blocked Account Stage | When you create a Sequence, you have the option to mark emails as Not Sent when an Account is in a given Account Stage. For example: ![]() |
You can change the stage of a specific Account that you want to send to or you can change the settings in the Sequence so that Apollo no longer blocks emails to any Accounts in that stage. When you have made this change, try sending the email again. |
Same Account Replied | If you have set the Sequence Rule to "not send" when another Contact from the same Account replies in the Sequence, Apollo does not send the email. ![]() |
Update the settings in the Sequence Ruleset and try resending the email. ![]() |
Unverified Email | If this is your first time sending an email to a Contact with an Unverified email, as a failsafe, Apollo does not send the email. | Unverified emails have a 60-80% success rate. Apollo recommends you try sending the email again. |
Missing Snippet | If you included Snippets in a message and the Contact you want to email does not have a value for this Snippet, Apollo does not send the email. | You can edit the Contact's profile to add a value for the missing field. Alternatively, you can change the Snippet to an Advanced Snippet and add a fallback for these types of scenarios. Please refer to the "Use Advanced Snippets" article for more information. |
Missing Thread Info | If you set the email Type as "Reply to a Previous Thread" and the Contact deletes the previous email, Apollo does not send the email. ![]() |
There is no ideal way to solve this issue. You can send this Contact a one-off manual email. Please note, if you want to make sure that the next emails in the Sequence also send, you need to adjust all other emails to send as part of a New Thread. |
No Send-From Mailbox Selected | When you add Contacts to a Sequence you have to assign a mailbox. If one of your teammates removes a mailbox to which you linked your Contact(s) in the Sequence, Apollo does not send the email. ![]() |
You can update an existing mailbox or choose to link another one. ![]() |
Email Missing or Invalid | If you added a Contact with no email address to your Sequence, Apollo does not send the email. | Update the email address in the Contact's profile. ![]() |
Contact Account Not Owned by User | Depending on your permissions, you may only have access to send emails to the Contacts of which you are the owner. If this is the case and you try to send an email to another user's Contact or Account, Apollo does not send the email. | You have 2 options to resolve this issue. Re-assign ownership of the contact or ask an admin to change your permissions so that you can send emails to other users' Contacts and Accounts. For more information, please refer to this section of the "Create Permission Profiles" article. |
Email Service Provider Error | If a Contact's email server is unable to deliver the email and returns an error to Apollo, Apollo cannot send the message. | There are many different causes for this type of error. Apollo provides additional information on a case-by-case basis. Hover your mouse over the "Email Service Provider Error" in Apollo to find out more. Use this information to troubleshoot the error yourself or reach out to the Apollo Support Team. Please note, the solution may involve making changes on the Contact's end. If this is the case, there is little Apollo can do to help. |
Other | Apollo uses this final category for emails that did not send but which Apollo cannot group into any of the reasons above. | Contact the Apollo Support Team for further information. |
Apollo Has Not Attempted to Send Your Emails
If Apollo has not tried to send your emails, there are 2 possible reasons for this:
- An admin in your team has deleted the user associated with the Contacts in your Sequence. To solve this issue, you need to first re-assign ownership of these contacts. Then, try sending the emails again.
- The time or date you scheduled the email to send has already passed. To solve this issue, edit the sending time for this step. For more information about how to do this, refer to the Reason 3: Verify Wait Time Between Steps section above.
How to Resend an Email
When you have diagnosed the issue, Apollo recommends you try to resend the email. Launch Apollo, click Engage, and then click Emails.
Apollo displays all emails under this tab, including any undelivered emails. Click the checkboxes next to the emails that you want to resend.
Then, click Retry Undelivered Emails.
Read the information in the Retry modal. Select the checkboxes if they apply to you and then click Retry.
Apollo notifies you if it can reschedule the email.