Why you get spam email and 4 ways to block it

It is really annoying to get lots of junk mail from Gmailevery day. So how do you keep that spam out of your inbox? The best way is to block the sender, so you no longer receive mail from that address. So how do you block spam email ?

In this guide, MONA shows MONA Media will show you how to block mail in Gmail effectively.

Why do you keep getting spam mail?

Spam emails come from many sources. See which of these you are dealing with!

Acquaintances or people you have interacted with

In this case, either the sender wants to harass you with spam, or they simply forgot to remove your email when sending.

This kind of spam from people you know happens most often when you leave a company where you used to work. People there may still know you but forget to remove your address, or do not know you have left, so they keep sending mail.

This is very common at large companies with many employees, where it is hard to control and coordinate information.

Spam from strangers

Your inbox surely has at least a few spam emails from people you do not know. They are usually advertisers trying to draw customers to their company or, worse, scammers. They may have found your address through:

• Guessing: Your email can be found by apps and software that generate email addresses. They usually cannot tell whether a generated address is real, so they send ads to every address they have.
• Hack: Even though email services today have fairly good security, they can still be hacked, and you may be one of the users whose email has leaked.
• Mua data: If you have joined prize draws or promotions that asked for your email address, it is very likely your email was sold to third parties. Buyers purchase the data, including email addresses, to send advertising.
• Scraping: Some tools scan for email addresses posted online (on Facebook or on websites). Spammers use them to send ads to the addresses they find.

So how do you block spam? Let's look at the details below with MONA.

Bullying emails

Cyberbullying is the English term for cyberbullying. These emails can come from people you know or from strangers. As the internet and social media grow, this is happening more and more. If you often receive bullying or harassing messages and you are the target, follow the steps below.

• Save the evidence: If you receive threatening emails, do not delete them right away. Take screenshots and keep the content as evidence to report.
• Report it: Report to the provider of the service you use that someone is threatening you. You can report the sender's account or report the email itself.
• Block the sender: If these people keep sending you emails, do not hesitate to block and remove them so unwanted messages do not appear in the future.

Gmail already has a very good built-in spam filter, but it is not perfect. You can apply the techniques below to help keep junk mail out of your inbox.

Explore the solution: Reliable email marketing services, run professionally

How to block spam in Gmail

Filter Gmail by sender

Blocking spam or filtering mail in Gmail is not hard. You can stop a specific person from sending you mail by blocking them, or move their mail into a separate folder.

Method 1: Block spam from a specific person in Gmail

You can block a specific person's mail in Gmail with these steps:

• Step 1: Open your inbox, open an email from the person you want to block.
• Step 2: Click the more options icon on the right side of the email, and a list of options will appear.
• Step 3: Click “Block + the sender's name” to block email from that person.

In this case, choose Block “Laura Spencer”, then a confirmation box appears asking you to confirm that future messages from Laura Spencer will go to your Spam folder.

• Step 4: In this step, just click “Block” to confirm.

If you want to unblock, click the more options icon and choose Unblock. A confirmation box will say that future emails from this person will show up in your inbox. Click Unblock to confirm.

Method 2: Block spam by filtering messages from a specific sender

You can block mail in Gmail with an email filter, which can be used to filter mail from a fixed sender.

• Step 1: For example, to filter all mail from a former employee, go to your Inbox and click the dropdown in the search box. The advanced search filter will appear.
• Step 2: In the From box, enter the sender's email and any other details. Then click “Create filter with this search”.
• Step 3: Tick the boxes that apply.

When a message matches your search, you have these options:

• • Mark as read: Mark as read.
  • Skip the Inbox (Archive it): Archive it.
  • Star it: Star it.
  • Apply the label: Apply a label.
  • Forward it (add forwarding address): Forward it (add the address you want to forward to).
  • Delete it: Delete it.
  • Never send it to Spam: Never send it to spam.
  • Always mark it as important: Always mark it as important.
  • Never mark it as important: Never mark it as important.
  • Categorize as: Categorize it.
• Step 4: Click Create filter at the left corner. A notice at the top will confirm that the filter has been created: Your filter was created.

Block spam in bulk

Through apps and software, advertising emails are sent in large volumes. If your email is on their list, the messages will reach you. Here is how to block spam in Gmail:

• Step 1: Use Unsubscribe in the search box.
• Step 2: Unsubscribe. You can unsubscribe through:

Method 1: The Unsubscribe link: Open the email and scroll to the bottom, where there is an Unsubscribe link. Follow the instructions or wait for the page to finish redirecting, and you will no longer receive mail from that sender.

Method 2: Gmail's own unsubscribe: If Gmail detects that an email has an unsubscribe button, it shows a link at the top of the email. Do the same as above: click unsubscribe and follow the instructions to block mail in Gmail.

Report to stop Gmail spam

Besides the methods above, you can block spam in Gmail by reporting it. Gmail has built a set of options for handling junk email, backed by a complex system of algorithms, which saves users time on filtering spam.

Emails are automatically recognized and sent to spam if they contain the following:

• No content.
• Impersonation of large companies.
• Financial or personal fraud information.

Or:

• From someone you have tried to unsubscribe from.
• The sender has not been verified.
• The email has been marked as spam.

How to block spam in Gmail:

Method 1: Report spam mail from your Gmail account

For emails you do not want to receive, mark them as spam. This helps Gmail learn which kinds of email you want to put in the spam folder.

• First, go to your Inbox. Tick the box to the left of the spam email and click the exclamation mark icon (Report spam) to report it.
• The email will immediately be moved to the spam folder.

Method 2: Move spam mail back to your inbox

If you marked an email as spam by accident, you can still move it back to your main inbox.

• Open your Gmail Spam folder by clicking Spam in the list on the left.
• Move the email that was marked as spam back to your inbox.
• If you cannot see the Spam folder, click More which appears just below the More option.
• In the Spam folder, tick the box next to the email you want to restore and click Not Spam to remove the Spam label. When you go back to your inbox, the message will be there.

Report phishing and impersonation

If you find an email that looks like fraud, an attempt to take your property, or impersonation of an organization or person, report it to Gmail or to the authorities.

Spam email is dangerous because the sender may be after your personal or financial information. These scams are sophisticated: attackers pose as financial institutions, government agencies and banks to steal data or money from users.

How to recover deleted spam emails

We have covered the ways to block email in Gmail above, but if you tag a message as spam, delete it and then realize it held important information, there is no need to worry too much.

A deleted email stays in Trash for 30 days before it is permanently removed. During that time you can restore it as follows:

• Step 1: Open Trash, choose the email you want to restore.
• Step 2: Click the Move above, then choose Move to Inbox. Your email will be restored right away.

According to Mr. Võ Nguyên Thoai, CTO of MONA Host: “Blocking junk mail in Gmail, or filtering out other unwanted messages keeps your inbox organized, shows you the important emails and lets you work more comfortably and productively.”

So how can you be sure your business email doesn't annoy people or get treated as spam? Take a look at business email service from MONA, with features that help your business promote itself and build a credible, professional brand image with customers.

With the information shared above, you now know how do you block spam email. If you have any questions, call hotline 1900 636 648 for advice and support.

→ You may be interested in:

• Full-service email marketing at an optimized cost
• What is phishing email? How to recognize scam emails and protect yourself

Send mail from your website or app without landing in spam

It is eleven at night and a customer has just placed an order on your website. Ten minutes later they are still waiting for a confirmation email. Your admin system says the email was sent successfully. The next morning the customer complains angrily, and when you check, the confirmation email is sitting in their spam folder. Every business owner has felt that at some point, and it means a lost customer.

Some people suggest running your own VPS to send mail cheaply, or using the SMTP of a personal Gmail account. Both are traps. Transactional email from these homemade setups is very easily flagged as spam by Google or Microsoft, because you share an IP range with thousands of other senders and that range has no reputation. Self-built servers also often lack required security signatures such as DKIM and a proper SPF record. According to the documentation we checked on 19/09/2026, a trial Gmail account can send only 500 emails a day, and a paid Workspace plan tops out at 2,000 a day. Go over the limit and the account is blocked from sending for up to 24 hours, so a large campaign gets stuck.

In the system mail flow of MONA Cloud, which we operate ourselves, the three notices for hitting a quota threshold or downgrading a plan go out automatically and do not count against the customer's quota. A cron job runs every five minutes, and customers can follow the status of each email through webhooks instead of guessing whether it arrived. Instead of risky manual setup, MONA Mail verifies your domain with a single DKIM record using the selector mona1, with RSA 2048 encryption to the proper security standard. When the system processes an email, it goes into the queue and the API immediately returns code 201 with the status queued. We never report delivered until the recipient's server has actually logged a successful delivery. If the receiving network has an error, the worker retries automatically after 1 second, 5 seconds, 25 seconds, 2 minutes and then 10 minutes before it reports failed through the webhook.

Sending costs very little. In the price list we checked on 19/09/2026, the Startup plan is only 99,000 VND for 30,000 emails, and anything over the limit is charged at 3 VND per email. The higher Business tier is 299,000 VND for 150,000 emails, and the system also gives you 3,000 free emails a month to try. When the wallet runs out, the API automatically returns error 402 and pauses emails over the limit, so there are no surprise invoices. One caution: a brand-new domain can still land in spam for the first few days, so you always need a proper warm-up plan from the start.

Don't use a personal Gmail SMTP to send automated email for a large system. You save a few dong today, and tomorrow you risk losing your core customers because an important email never arrived. It is too risky.

Server and domain infrastructure built for SEO, from MONA Cloud

Clients who come to us for a system often describe the same scene: the website goes down during a flash sale because traffic spikes, and the technician spends the whole morning fumbling to restart the server because the self-built configuration is too tangled. Thousands of orders can't be paid for and customers go buy elsewhere. MONA Mail is free for 3,000 emails a month, and the Startup plan is 99,000 VND for 30,000 emails, with 3 VND per extra email, based on the figures we checked on 19/09/2026.

Most business owners dread complicated technical work, and the more people touch the code, the more mistakes creep in. Configuring a server by hand wastes time and can open serious security holes. That is when you need infrastructure built for automation. MONA Cloud is The MONA Group's AI-friendly server platform: very fast for clients in Vietnam, rented by the hour and paid in VND. You log in through Claude Code, and the AI creates the virtual machine, deploys the source code, attaches the domain and hands back a secure link for you to continue with.

Billing is fully transparent. You pay only for the resources you use, by the hour, at a low rate for each hardware configuration. When you shut a machine down, CPU and RAM charges stop automatically, and you top up only what you will use. That ends paying for idle running time. Every transaction comes with a valid VAT invoice. The system includes a bank API and an automatic payment confirmation service to keep operations smooth. Choose MONA because you pay in VND, your data is stored in Vietnam, and a support team is always there.

To round out the ecosystem, we also offer MONA Domain at a reasonable price, so you can manage all your digital assets in one place. Registering a .vn domain is quick now: you only need eKYC and a digital signature once. The AI can also look up a domain, reserve it immediately with a VietQR code without an account, and then set the DNS correctly. Handing this to the AI shortens a tedious process.

Don't configure a VPS by hand if you don't have deep expertise. A real business system needs solid infrastructure from the foundation, and letting the AI and an optimized platform do it is the safest way. Mistakes cost money.

A manifesto for growing together

MONA is a software, digital transformation and AI transformation company, but above all, MONA is a B2B service company that benefits directly from this: THE MORE SUCCESSFUL VIETNAMESE BUSINESSES BECOME, THE MORE MONA BENEFITS, while a declining, slow market with weak technology is exactly what kills MONA's future business opportunities. So, more than anyone, MONA wants you to succeed, and MONA actually steps in to help you succeed.

And AI transformation is the key to that success for all of us.

MONA

Start automating your business systems today

A smooth-running system doesn't appear on its own. MONA Mail is free for 3,000 emails a month, with a webhook for the status of each email. Try it first at https://monamail.vn/, which takes about 5 minutes. One click and it's done.

Try MONA Mail with 3,000 free emails Call 1900 636 648

FAQ

Why do I keep getting spam emails even though I never signed up?

Your email may have leaked in several ways: address-guessing software, data breaches, data bought from third parties after you joined a promotion, or scraping tools that collected it from Facebook or websites.

How do I recover a spam email I deleted by mistake in Gmail?

Deleted emails stay in Trash for 30 days before they are permanently deleted. To recover one, go to Trash, select the email, click Move and choose Move to Inbox.