If you sent an email from the Lead Database (as a Single Flow Action), as part of a campaign, or as a test email but didn't receive it, here are some tips.
When sending a test message, make sure to check the "From:" address setting on your message. To do this, go to the Email Settings tab of the email editor. In the "From:" field, make sure that you either have a single valid email address, or a valid email address as the default.
Many people want to send their messages from the lead owner. When you use the send test feature, the email address you are sending to doesn't have a full lead record, and so it doesn't have a lead owner. Since Marketo cannot send an email with no "From:" address, test messages without a valid email address in the "From:" field will not send.
If you have verified that the email had a valid From: address and you still aren't getting it, make sure to create yourself as a lead and send using a flow action.
If you sent the email as part of a campaign or Single Flow Action, check the campaign's Results tab or your lead detail page to see if that mail was already sent to you. If it hasn't been sent yet, try waiting a little while longer.
In your email client, check your Junk Mail or Spam folder to see if the mail landed there. If it did, you should change the content of your email.
Your corporate mail server may have blocked emails from Marketo; you should contact your IT department to see if this is the case. Please see our instructions for whitelisting Marketo's email servers: Add Marketo to Your Corporate Email Whitelist
If you sent the original mail to your corporate account, try sending to a personal account on Yahoo or Gmail. If you sent it to a personal account, try your corporate mail account.
The Email Deliverability PowerPack, with Design Informant and Inbox Informant, can warn you when your mail is being rejected because of its content and help you identify junk mail pitfalls. Also, using Domain Keys and SPF improve the chances of your email landing in your leads' inboxes.
If you still can't figure out what happened contact Marketo to see if we can help.