Invalid email wasted sends calculator: what a bad list costs a sequence
In short: Enter the leads in a sequence, the share of invalid addresses, how many emails the sequence has and how many an invalid address receives before your tool suppresses it. You get the bounces, the bounce rate on the first email and across the sequence, and the days of sending capacity they use. Limit: The invalid share is your estimate; the real share is only known after verification.
Invalid addresses turn into bounces at the first email, and into more bounces at each later step if your tool keeps trying. Type the leads, the invalid share, the sequence length and how many emails each invalid address gets. The calculator shows the bounces, the bounce rate on the first email and across the sequence, and the capacity used.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. Check your list free nowSee pricing
The numbers below are examples. Replace them with your list size, the invalid share from a check and how your sequencer behaves.
From a verification report, or your own estimate.
The first email counts as one.
1 if your tool stops at the first hard bounce; up to the sequence length if it keeps going.
- Invalid addresses
- 360
- Emails that bounce
- 360
- First-email bounce rate
- 12%
- Bounce rate across the sequence
- 3.3%
- Days of sending capacity used by bounces
- 1.2
Of 12,000 planned emails, 360 go to addresses that do not exist. Removing those addresses first leaves 2,640 leads and no bounces from this cause.
1
- Sent
- 3,000
- Bounces
- 360
- Bounce rate (%)
- 12
2
- Sent
- 2,640
- Bounces
- 0
- Bounce rate (%)
- 0
3
- Sent
- 2,640
- Bounces
- 0
- Bounce rate (%)
- 0
4
- Sent
- 2,640
- Bounces
- 0
- Bounce rate (%)
- 0
| Sent | Bounces | Bounce rate (%) | |
|---|---|---|---|
| 1 | 3,000 | 360 | 12 |
| 2 | 2,640 | 0 | 0 |
| 3 | 2,640 | 0 | 0 |
| 4 | 2,640 | 0 | 0 |
Formula: invalid addresses = leads x invalid share; bounces = invalid addresses x emails each gets before suppression. The shares are your inputs, not measured figures.
Sample result
In the example, 360 invalid addresses bounce on the first email: a 12% rate there and 3.3% across the sequence.
- Emails that bounce
- 360
- First email
- 12%
- Whole sequence
- 3.3%
What this means for you
Those bounces take up 1.2 days of sending capacity that valid leads could have used.
- Your invalid share
- Rate per email
- Capacity used
- Download the table
- Bounces
- Sequences
- Calculator
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Replace the invalid share with a real count.
- Export the leads that are about to enter the sequence, one address per row.
- Upload or paste it at /verify. Every address gets a live mailbox check, and the first 100 email checks are free with a Google sign-in, no card.
How do I estimate wasted sends from invalid emails?
- Type the number of leads in the sequence and the share of addresses you expect to be invalid.
- Type how many emails the sequence has, counting the first one.
- Type how many emails an invalid address receives before your tool suppresses it: 1 if it stops at the first hard bounce.
- Add your daily sending capacity and the cost of one email if you want them counted.
- Read the bounces and the per-email table, then verify the list so those addresses are never sent to.
Example
- You enter
- Example: 3,000 leads, 12% invalid, a 4-email sequence, invalid addresses get 1 email before suppression, 300 emails a day of capacity.
- You get
- 360 invalid addresses produce 360 bounces: a 12% bounce rate on the first email and 3.3% across the sequence of 10,920 emails sent. Those bounces use 1.2 days of sending capacity.
- Limits
- Runs in your browser; nothing is uploaded. Every number is typed by you; the values here are examples.
How are the wasted sends worked out?
Invalid addresses are the leads times the invalid share. Each one receives the number of emails you typed before it is suppressed, and every one of those emails bounces. The bounce rate across the sequence is the bounces divided by all emails actually sent, which are the valid leads times the sequence length plus the emails sent to invalid addresses.
Why does the first email matter most?
If your tool suppresses an address after the first hard bounce, every invalid address bounces once, all on the first email, so the first email carries the full invalid share as its bounce rate. If it keeps sending, the bounces repeat at each step. The table shows the bounce rate for every email in the sequence so you can see which case applies.
What about the cost?
Capacity is counted in days: the bounced emails divided by what your mailboxes send in a day. The cost is the bounces times the cost of one email, if you typed one. Neither includes the harm to sender reputation that bounces can cause. For how platforms treat bounce rates, see bounce rate thresholds by platform.
Who uses this tool, and for what?
- Cold emailers
- Show how much of a campaign's sending goes to addresses that cannot receive it.
- Agencies
- Explain to a client why a list is checked before it enters a sequence.
- Sales ops
- Estimate the capacity a sequencer loses when invalid leads are imported.
What can’t this tool tell you?
- The invalid share is your estimate; the real share is only known after verification.
- It models only addresses that do not exist, not full inboxes or blocks.
- It applies the same number of attempts to every invalid address.
- It does not price the effect of bounces on sender reputation.
Common questions
- What invalid share should I type?
- The share marked invalid in a verification report of a similar list. If you have none, use an estimate and treat the result as a rough size.
- What does emails per invalid address mean?
- How many emails an invalid address gets before your tool stops. Check your tool's bounce handling to find out.
- Does it count soft bounces?
- No. It counts addresses that do not exist, which is what verification removes.
- Why can the sequence bounce rate be lower than the first email's?
- Later emails go only to addresses that did not bounce, so they dilute the rate.
- Does it predict my real bounce rate?
- No. It is arithmetic on the shares you type.
- Is anything uploaded?
- No. The numbers stay in your browser.
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.