Daily bounce rate tracker: spot the day your bounces climbed
In short: Paste a date, emails sent and bounces for each sending day. You get the bounce rate for every day, a rolling rate over the window you pick, the days over a line you set, the worst day, and how many clean sends it would take to bring the rolling rate back down. Limit: It uses the numbers you paste; it does not read any account.
Paste one line per sending day with the date, the emails sent and the bounces. The tracker gives each day's bounce rate (bounces divided by sent), a rolling rate over the last days you choose, and marks the days over a line you set yourself. It also shows the worst day and how many more clean sends would pull the rolling rate back to your line.
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
Copy the three columns from your sequencer's daily report or a spreadsheet. A header line is ignored; the same date twice is added together.
The rate you will not let a day or a week pass. The 2 is an example; use your own rule.
Calendar days ending on each date.
Sample result
5 November bounced at 4%, and the latest 7-day rate is 2.22% against a 2% line.
- Days over the line
- 2 days
- All days
- 2.05%
- Worst day
- 4%
What this means for you
The spike is dated, so you can look at what was sent that day and check the list behind it.
- Rate for every day
- Rolling window you pick
- Your own line
- CSV download
- Bounces
- Daily
- Trend
By SimpleVerifier Team · Last updated · Runs in your browser; nothing you paste is sent to us
Bounces start with the addresses on the list.
- Take the list behind the days that bounced, or the next list you plan to send.
- 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 track my bounce rate day by day?
- Copy three columns from your sequencer's daily report or a spreadsheet: the date, the emails sent that day and the bounces that day, one line per day.
- Set your own bounce-rate line and the rolling window in days. The pre-filled 2% and 7 days are examples.
- Read the stats, the worst day and the table. Days and windows over your line are marked.
- Download the CSV, and look at which campaign, list or inbox was sending on the days the rate jumped.
Example
- You enter
- Seven days of lines from 2 to 9 November (one date missing): 300 sent and 3 bounced, 320 and 4, 310 and 5, 350 and 14, 340 and 12, 120 and 1, then 360 and 4; a line of 2%, and a 7-day window.
- You get
- The bounce rate over all seven days is 2.05%. 5 November is the worst day at 4%, and two days are over the line. The latest 7-day rate is 2.22% (40 bounces from 1,800 sends), so about 200 more sends with no new bounces would bring it to 2%.
- Limits
- Runs in your browser. The line and the numbers are the ones you enter.
How is the daily and rolling bounce rate worked out?
A day's bounce rate is the bounces that day divided by the emails sent that day. The rolling rate adds up the bounces and the sends over the calendar days ending on that date and divides one by the other, so a small day does not swing it the way it swings a single day's rate. Dates missing from your paste count as days with nothing sent. Nothing is compared with a published limit: the line is whatever you set.
What do I do with a day that is over my line?
Look at what was different that day: a new list, a new source, a new inbox or a resumed campaign. Bounces come from the addresses you sent to, and a permanent failure is reported with a 5.x.x status in the enhanced status code form, so the bounce messages say which kind of failure it was. The bounce rate calculator compares a rate with each platform's own published lines, and the bounce analyzer reads the messages.
Why does the tool say how many clean sends bring the rate down?
Because the rolling rate is a fraction, adding sends that do not bounce makes it smaller. The tool shows that arithmetic for the latest window: the sends that would put the bounces at exactly your line if nothing else bounced. Whether it is wise to send that volume is a different question; clean the list first so the new sends do not bounce either.
Who uses this tool, and for what?
- Cold email senders
- See whether a bounce spike lines up with a new list or a new inbox, and how the rolling week looks.
- Agencies
- Add a daily bounce table to a client report with the days over the client's own line marked.
- Deliverability consultants
- Pin down the date a problem began before asking what changed that day.
What can’t this tool tell you?
- It uses the numbers you paste; it does not read any account.
- A bounce rate says nothing about spam-folder placement or replies.
- Write the counts as whole numbers without thousands separators, because commas split the line.
- Bounces that arrive late are counted on the day your report shows them, not the day of sending.
Common questions
- Where do I get the daily numbers?
- Most sequencers and email platforms show sends and bounces per day or per campaign in their reports. Copy them into three columns; this tool does not connect to any account.
- What line should I use?
- That is your rule. Platforms publish their own lines; the bounce rate calculator lists them with links. The pre-filled 2% is an example.
- Does a missing date count as a day with zero bounces?
- It counts as a day with nothing sent, so it adds nothing to either number. The tool tells you how many dates are missing.
- Can I paste more than one campaign?
- Yes, but lines for the same date are added together. To compare campaigns, run each one separately.
- Is my data uploaded?
- No. The lines are read and calculated in your browser.
Sources
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.