Why Are Some E-Mails Not Delivered?

November 30, 2020 15:37

This article explains why it can happen that some documents and/or notifications are not delivered to the specified recipient.

E-Mail receipt status

eversign is using Mailchimp for transactional e-mails, they distinguish between 5 statuses of e-mail (3 for undeliverable) and also use a rejection list to manage the sheer amount of e-mails requested every day.

Delivered or Spam

The e-mail got delivered successfully (SMTP has a delivery confirmation) but it isn't visible in the inbox.

The e-Mail from eversign got reported as spam.

👉 as soon this happens, the e-mail address gets added to the 🏴 rejection list for 365 days and you won't receive anything from eversign.

Bounced or Rejected

The e-Mail address or server exists/is reachable, but our attempt to send a message got rejected.

👉 as soon this happens, the e-mail address gets added to the 🏴 rejection list for the next 24h and you won't receive anything from eversign.

The e-mail address or server does not exist/is not reachable

👉 as soon this happens, the e-mail address gets added to the 🏴 rejection list for the next 1-7 days and you won't receive anything from eversign.

The e-mail address is on the rejection list for 24h because of a 🟡 soft-bounce
The e-mail address is on the rejection list for 1-7 days because of a 🔴 hard-bounce

🏴 rejection list

While an email address is active on the rejection list, emails to the address will be given a state of rejected and eversign won't try to deliver the emails. This helps prevent sending emails to an email address that is no longer valid, maybe having temporary issues, or doesn't wish to receive emails from you.

After a rejection expires, if an email is sent to the address, eversign will attempt to deliver the message. Subsequent bounces, spam complaints, or unsubscribe attempts result in an address being added to the rejection list for longer periods of time.

Some examples for the duration of blacklisted emails.

Bounce type	Bounce message	Duration
🟡 soft-bounce	smtp;550 Mailbox is full / Blocks limit exceeded / Inode limit exceeded	5 days

Most common reasons why an E-Mail isn't visible / receipt

Below you can find a brief explanation of the most common cases:

🟢 Marked as spam

It can happen that e-mails from eversign are flagged as spam. You can simply retrieve it from your spam/junk folder.

🟢 E-Mail quarantined

Some mailboxes have also so-called "quarantined" e-mails, it blocks incoming messages on a higher level than your inbox and therefore you or an administrator needs to allow it. The reasons for this can vary in every case, but it already happened when you sent a contract to 10+ persons of the same company, then their email server can think it's a spam attack. Here's an example of how it works with Office 365.

🟡 Full inbox

Many e-mail servers have a default inbox size of 1GB, our attempt to send a notification is blocked because the inbox is full.

🟡 Attachment too big

Many e-mail servers have a default limit of 20MB, our attempt to send the completed document is blocked.

🟡 External e-mail to a group

Many e-mail servers do not allow external messages to a group by default. Here's how to fix it for Gsuite.

🟡 Use of Mimecast or other e-mail security platform

Mimecast

The sending mail server is subjected to Greylisting.: These reputation checks can be bypassed with an Auto Allow or Permitted Senders policy. If it's legitimate traffic, amend your Greylisting policy. reputation checks can be bypassed with an Auto Allow or Permitted Senders policy. If it's legitimate traffic, amend your Greylisting policy.

All other Mimecast topics are here.

🔴 E-Mail does not exist

The e-mail does not exist, either because it's a typo or there's an unknown error with your server.

🔴 E-Mail server not available

Your e-mail server was down / was not available to receive messages.

🔴 Marked as spam

You marked any previous eversign e-mail as spam.

🔴 Bad actor

You are blocked by our transactional e-mail provider because your email got reported within their network by someone else.

🆕 13th November 2020

eversign exposes now the bounce details on document level in your account.

💡 In this scenario, there was a wrong email address used, which domain does not exist.