General
May 24, 2023

Product Update - Safety Net

The Email Safety Net from Allegrow, saves you from sending emails that harm spam rate & inbox placement. Integrates to sales engagement for deliverability.

Product Update - Safety Net

Allegrow doesn’t just help the emails that you send land in the primary inbox. We also stop you from sending emails which will harm your sender reputation with our new Safety Net module. 

The Safety Net analyzes each email that’s scheduled inside your sales engagement platform and reverts risky emails to drafts. This allows you to prevent bounces, blacklisting and manual spam reports on your emails. 

You’ll then have the opportunity to analyze each email the Safety Net catches and take appropriate next steps with enhanced email deliverability. 

We now live in a world where for your entire company, the emails you chose to not send are just as valuable as the ones you do!

Therefore, without a safety net which has your back and helps catch bad data or risky contacts that slip into outbound email processes, the deliverability of your entire company is put at risk.

In this guide, we’ll outline:

What is a bounce

An email bounce is when your message was either rejected or could not be delivered to the recipient's mail server. Hard bounces are when an email has permanently failed to deliver to a server, whereas a soft bounce indicates future delivery may be possible. 

Here are some examples of common types of bounces:

Hard Bounces:

  • 5.1.0: Something about the address specified in the message caused this Delivery Status Notification.
  • 5.1.1: The mailbox specified in the address does not exist.
  • 5.1.2: The destination system specified in the address does not exist.
  • 5.1.3: The destination address was syntactically invalid.
  • 5.1.4: The mailbox address as specified matches one or more recipients.
  • 5.1.6: The mailbox address provided was at one time valid, but now it is not.
  • 5.1.8: The sender's system specified in the address does not exist.
  • 5.2.0: The mailbox exists, but something about the destination mailbox caused the sending of this Delivery Status Notification.
  • 5.7.1: Often seen when the email has been blocked by the recipient's email security system, due to content appearing similar to spam, or being in a group explicitly blocked by the recipient.

Soft Bounces:

  • 4.2.2: The mailbox is full because the user has exceeded a per-mailbox administrative quota.
  • 4.3.1: Mail system storage has been exceeded.
  • 4.3.2: The host on which the mailbox is resident is not accepting messages. Sometimes seen when a server has taken action to protect against spam or other email abuse.
  • 4.4.1: The outbound connection attempt was not answered. This can sometimes happen if the recipient's email server has been blacklisted due to spam.
  • 4.4.2: The outbound connection was established, but was unable to complete the message transaction.

General Bounces:

  • 5.5.0: Something was wrong with the protocol necessary to deliver the message to the next hop. This catch-all error sometimes includes spam-related bounces, but would usually include more specific information in the bounce message.
  • 5.5.1: A mail transfer protocol command was issued which was either out of sequence or unsupported.
  • 5.5.2: A mail transfer protocol command was issued in such a way as to be malformed.
  • 5.5.3: More recipients were specified for the message than could have been delivered by the protocol.

A small number of bounces can be expected in day-to-day operations; however, when you conduct outbound sending, the risk profile of producing bounces that will hurt your sender's reputation drastically increases.

Why your Current Process puts Deliverability at Risk

Your team will regularly source emails of contacts at accounts you’ve assigned them, then add these contacts to your sales engagement software to conduct an outbound sequence. 

Inevitably, regardless of the internal best practices and data provider, risky contacts find their way into your outbound sequences. Then when outreach emails from your users' mailboxes and company domains are sent to these emails, bounces are produced.

As these bounces pile up over time and are produced at a higher rate than average by your domain, this sends a signal to email providers that you don’t know the contacts you’re reaching out to and are conducting risky email behavior. Therefore, the future inbox placement of your domain and mailboxes will be impacted - meaning more of your emails get delivered to the spam folder or get blocked. 

The average bounce rate on automated emails across all industries is 0.40%, while specifically outbound campaigns usually have a higher bounce rate. Benchmarking from Outreach suggests a bounce rate of over  2.8% indicates it’s highly likely your emails are being flagged as spam. 

To help neutralize the risk outbound sequences pose to your email reputation, an email safety net acts as a final line of defense against risky contacts being messaged and hurting your domain.  

How to use our Email Safety Net (in 3 Steps)


Rather than conduct basic data verification on email contacts on a periodic basis, the Safety Net dynamically checks contacts moments before your emails are about to be sent, preventing slip-ups. 

This means the Allegrow Safety Net has your back and protects your team's deliverability, so you can focus on prospects rather than analyzing your contacts for deliverability risk.

There are three core steps to the Safety Net’s process:

Step 1: Every contact which gets scheduled inside your sending software will be checked shortly before it gets sent to. 

Step 2: While analyzing each contact, if we detect the recipient is too risky. We’ll revert the email back to a draft so it doesn’t get sent to or enter your sequence.

Step 3: Then we’ll notify your team/rep, showing them the reason sending was prevented. This allows you to take the best possible next step while maintaining high deliverability. 

Potential steps you might take after notification a contact was caught by the safety net are; selecting a different contact at the same account to prospect, or reaching out to the prospect through a different communication channel. 

*Remember - In order for your traffic to be run through the Safety Net, you'll need to have a small delay set inside your sequence steps of 2-minutes minimum so we have time to conduct analysis on the email and revert it to draft (if necessary). To make sure this is in place you can check your sequence steps like this:

Look for the '10 minutes' and 'Edit step' if you need to

If you need to add a delay, select 'Editing step' - then proceed to set 'After a set amount of time' as the option for the sequence, and fill 2-mins as the minimum delay:

On the other hand, if you're sending an email directly from Outreach rather than through a sequence and want it to be run through the Safety Net, select the 'Send later' option once you've complete your draft and schedule the email for at least 2 mins in the future:

What analysis the Safety Net conducts

The Allegrow Safety Net connects to your sending software and conducts analysis to identify the contacts you are about to reach out to, that could hurt your sender reputation.

When we detect a high-risk email inside your sending schedule, we’ll revert the email back to a draft, so that automatic sending does not occur. While conducting this analysis, we look to evaluate multiple aspects of each email contact. This includes but is not limited to, the following areas:

  • If the recipients' mail email server is operational. 
  • Syntax of the email address. 
  • Data sources that suggest the address may have a history of producing bounces. 
  • If the contact is a secondary or primary email address. 
  • If the recipient has a track record of manually reporting or blacklisting mail. 
  • If the email being contacted is a ‘spam trap’.
  • When was the last known engagement the recipient email had with incoming emails. 

The safety net cannot reduce your bounce rate to zero - however, it can help as a final line of defense to remove risky contacts from your outbound email flow. 

Next Steps After an Email was Prevented

When the Safety Net prevents an email, this is an opportunity for you to extract more value from every outbound email you send, helping you to increase open and reply rates and avoid your emails landing in spam folders. 

As there are various reasons for emails being prevented, the potential next steps you can take will vary depending on the reason code. We’ve outlined the most common reasons and next steps you may want to take in each instance below:

Invalid Email

When you see this status code, it means we’ve evaluated the email you’re looking to contact and concluded it’s highly likely to produce a bounce which can hurt your sender reputation. 

The best next steps following this are:

  • Find an alternative contact to reach out to inside the same company. Then proceed to add this attentive contact to the same sequence we’ve removed the initial prospect from.

  • If there is no alternative contact which meets the criteria to be a prospect for you, then you will want to add this prospect to a sequence which does not include email steps. (For example, a sequence only composed of a LinkedIn connection request, multiple outbound calls and LinkedIn DMs).

  • In the instances where you cannot find another contact at the same company, and a ‘no email cadence’ is not feasible for you to conduct, simply move on to following up with your alternative accounts and do not email this contact or prospect the account in general. 

Catch-all Email 


This status means the company you’re reaching out to has put a setting in place where all email traffic to their domain will be accepted, even if the address is incorrect.

This setting makes contacting email addresses from these companies higher risk due to the following reasons.

1) Incorrect messages are often re-routed to a mailbox within the org where there is a high risk of manual reports + negative engagement.

2) Data providers will frequently have incorrect or secondary addresses listed as the prospect details for companies with this setting in place. 

Therefore, you’ll want to limit the overall volume of automated prospecting emails you send to contacts that provide catch-all results. When one is prevented by the Safety Net, the potential best next steps to conduct are as follows:

  • When you have a relatively high volume of data and accounts being provided and your sequence is fully automated. You’ll want to only use your daily sending limits to prospect low-risk emails. Therefore, simply proceed with prospecting other contacts and accounts. 
  • If you need to continue prospecting the account, you’ll want to add this prospect to a sequence which has a lower number of email steps than your typical sequence. (For example, a sequence only composed of two emails and LinkedIn connections request, with multiple outbound calls and LinkedIn DMs).
  • In the instances where you’re certain the prospect is valid due to prior engagement. You’ll want to bypass the Safety Net and send the emails as we outline here

Currently, the standard implementation of the Safety Net does not prevent sending to emails which fall inside this general category. Our future implementation will allow you to specify on a per-sequence level if you want to limit catch-all sending.

Spamtrap Email

When you see this status code it means we’ve evaluated the email you’re looking to contact and concluded it’s highly likely to be a spam trap. This means if you contact the email it will land you on a blacklist and hurt your deliverability. 

The best next steps following this prevention are:

  • Find an alternative contact to reach out to inside the same company as the existing prospect. Then proceed to add this attentive contact to the same sequence we’ve removed this prospect from.

  • If there is no alternative contact which meets the criteria to be a prospect for you, then you will want to add this prospect to a sequence which does not include email steps. (For example, a sequence only composed of a LinkedIn connections request, multiple outbound calls and LinkedIn DMs).

  • In the instances where you cannot find another contact at the same company, and a none email cadence is not feasible for you to conduct. Simply move on following up with your alternative accounts and do not email this contact or prospect the account in general. 

Do Not Mail & Abuse

When you see this status code ‘Do_not_mail’, it means we’ve evaluated the email you’re looking to contact and concluded it’s likely sending any cold email to this contact will result in a manual spam report, which can hurt your deliverability and get your mailbox suspended. 

The best next steps following this prevention are:

  • Find an alternative contact to reach out to inside the same company as the existing prospect. Then proceed to add this attentive contact to the same sequence we’ve removed this prospect from.

  • If there is no alternative contact which meets the criteria to be a prospect for you, then you will want to add this prospect to a sequence which does not include email steps. (For example, a sequence only composed of a LinkedIn connections request, multiple outbound calls and LinkedIn DMs).

  • In the instances where you cannot find another contact at the same company, and a none email cadence is not feasible for you to conduct. Simply move on following up with your alternative accounts and do not email this contact or prospect the account in general. 

Secondary Email

When you’re running an efficient outbound process you want to make sure your sequence, goes to the very best contact within your target account. With today's strict spam filters, every additional person you need to add to a cold cadence increases your spam risk.

With this in mind, a lot of your most senior decision markers will have multiple email accounts. Only one of these mailboxes will be the one they use for managing their business communications, whereas the others will likely be maintained by someone who isn’t the decision maker and a bad fit to target for prospecting. 

Due to the way data providers gather information, these ‘secondary_email’ accounts can end up in your prospecting sequence. So you have the best opportunity of getting engagement Allegrow evaluates and identifies cases where the mailbox you’re targeting is not the decision maker's primary email address, so you can avoid wasting resources and increasing your spam risk by chasing a secondary email account. Therefore, when you receive this prevention code, the best next steps to take are:

  • Check whether you have another email listed for the same decision maker from another sales intelligence provider. Then if you do, enroll this different email to the same prospecting sequence. 
  • In cases where you cannot find an alternative email, you will want to evaluate if there is another decision maker you can find an email for at the company that is a better fit to receive your prospecting message. Then enroll their email instead. 
  • Or if you cannot source any additional emails, you will want to move the prospect to a sequence that has no automated email steps and primarily relies on other channels.


Unknown Email

Occasionally, the risk analysis we run will indicate some risk, but be inconclusive overall. In these instances, rather than letting the contact slip through your Safety Net - we’ll prevent it so your deliverability is protected and more analysis can be run before contacting the email. 

When you see this prevention code, the best next step to conduct is as follows:

  • Re-enrol the contact into the same scheduled sequence step of your sending platform. Then the Safety Net will proceed to run additional risk analysis as the contact is scheduled to be emailed.

  • If you see the contact is prevented from being sent to multiple times in a row and returns the same ‘Unknown Email’ status code. We’d advise finding an alternative contact to reach out to inside the same company as the existing prospect. Then proceed to add this attentive contact to the same sequence we’ve removed this prospect from.

  • If the alternative contact you reach out to produces the same unknown code it’s likely there is an issue with the companies email systems. Therefore, move on to prospecting different businesses and potentially re-try prospecting a contact from this business after 30 days. 

Low Engagement Email

We also run analysis on how receptive contacts who you plan to reach out to are to prospecting in general. Therefore, when you see the status code ‘Low_Engagement_Email’, we’ve established the mailbox has less history of engagement with prospecting emails and a higher likelihood of producing a bounce on average.

Therefore, the best next steps when this status code is shown, based on your judgment are as follows:

  • Find an alternative contact to reach out to inside the same company as the existing prospect. Then, proceed to add this alternative contact to the same sequence we’ve removed the initial prospect from. 
  • If there is no alternative contact which meets the criteria to be a prospect for you, then you will want to add this prospect to a sequence which does not include email steps. (For example, a sequence only composed of a LinkedIn connection request, multiple outbound calls and LinkedIn DMs).
  • In the instances where you cannot find another contact at the same company, and a ‘no email cadence’ is not feasible for you to conduct, simply move on to following up with your alternative accounts and do not email this contact or prospect the account in general. 

Compatibility & Email Safety Net Set-Up

For the Safety Net to start working on your Allegrow account you’ll need to connect Allegrow to your sales engagement platform and have the mailboxes which conduct sending in your sales software, also connected to your Allegrow account.

Instructions on setting up the Safety net in your Allegrow account are available here

Currently, the Safety Net is compatible with Outreach.io, Salesloft and Close CRM. You can review integration-specific summaries for each system by selecting your vendor from the list available here.

You can find our fully approved marketplace listings on each of those respective vendors publicly available sites as follows:

1) The Outreach Marketplace:

2) The Salesloft Marketplace:



3) Close CRM Integrations:



If you use a different sales engagement / sending software that you’d like to connect to the Safety Net - Don’t Worry, we’ll be adding more integrations very soon. But, if you’d like the one that matters to you most to be prioritized, please let us know by discussing your use-case with us here