Fazley Rabbi"We sent our first email campaign and a big part of it bounced back. Now even our normal emails to customers seem to go to spam." This happens to many businesses that send to an old list, to cards collected at fairs over several years, or to a list someone pieced together from many sources. The fix is to verify the list before you send, and then keep it clean.
Why bounces matter
A bounce is an email that could not be delivered. A hard bounce means the address does not exist or the domain cannot receive mail; it will never work. A soft bounce is temporary: a full mailbox, a server that is down, or a message that was too large.
Email providers notice when a sender keeps hitting addresses that don't exist. To them it looks like someone using an old or bought list, which is what spammers do. Your sender reputation drops, and then even your real emails to real customers are more likely to land in spam. So checking a list protects more than one campaign; it protects your domain.
Where bad addresses come from
- People change jobs and their old work address is closed.
- Typing mistakes when cards from trade fairs or paper forms are entered by hand.
- Guessed addresses, such as firstname@company, that were never confirmed.
- Lists bought or copied from somewhere. Apart from the bounces, sending to these is not ethical outreach and can break the rules in the recipient's country. Don't use them.
- Companies that have closed or changed their domain name.
How to verify a list, step by step
- Bring everything into one sheet. One row per contact, with columns for where and when you got the address.
- Remove duplicates and obvious errors. A missing "@", spaces, or misspelled domains such as "gmial".
- Run the list through an email verification tool. These tools check that the address is written correctly, that the domain exists and is set up to receive mail, and, where possible, whether the mailbox responds. They usually sort results into groups such as valid, invalid, risky or unknown.
- Decide what to do with each group. Send to valid addresses. Delete invalid ones. For risky or unknown addresses, including "catch-all" domains that accept everything so a single mailbox can't be confirmed, either find another contact or send to them separately in small numbers.
- Look at role addresses on purpose. Addresses such as info@ or sales@ are often real but read by many people, or by no one. Keep them only when there is no named person to contact.
- Send in small batches first. Watch the bounces before sending to the rest.
- Clean up after every send. Remove hard bounces at once. Remove soft bounces that keep failing.
What verification cannot do
A verification tool tells you an address probably exists. It does not tell you the person wants to hear from you, and it does not make a bought list acceptable. Results also age: people keep changing jobs, so a list checked months ago needs checking again. Every email you send should still say who you are and give an easy way to opt out. Bounces are one part of reaching the inbox; domain setup and sending habits are the other, covered in why cold emails land in spam.
In-house or with help
Removing duplicates, fixing typos and recording sources is work your team can do in a spreadsheet. Outside help is worth it when the list is large, comes from many sources, or when your domain already has a reputation problem that needs to be diagnosed alongside the clean-up.
Before your next campaign
Take the list you plan to use, remove duplicates and add a "source and date" column. Then verify only the addresses you plan to email this month, not the whole archive. If you'd like a hand, see lead generation and B2B outreach or get in touch.