18 december 2024, 14:02
164
In email marketing, we usually evaluate a campaign’s success by measuring its most important metrics, such as deliverability, opens and click rates. However, all this makes sense only if your messages were actually sent. But what if the emails just fail to leave your outbox? Why may this happen, and how to fix it?
If, after hours of designing emails and configuring your email service, you get the error “Failed to send email,” this effectively halts your campaign until you can fix the problem.
So why are emails not sent? Perhaps you have encountered similar issues and are wondering about the possible causes? If so, you’ve come to the right place. Below, you’ll learn about the common reasons behind such problems and discover how to fix the “emails not sending” problem.
What Does the Message «Failed to Send Email» Mean?
This error, or more specifically the failure message provided by your email client or service, may be caused by connectivity problems, wrong settings, issues directly related to the message itself, and so on. Usually you’ll see it as a popup right after you click the Send button, although sometimes it may appear later in your mailbox.
There are several possible causes for this error, which can make it difficult to identify and resolve. The error message itself may not contain enough information to help you pinpoint the exact problem. If you’re facing such issues, start by focusing on identifying the root cause.
Top Reasons Why Your Emails Are Not Sending
Why can’t I send emails? There are several possible reasons for this issue that you should check one after another, namely:
- Internet connection issues
- Email server problems
- Incorrect SMTP settings
- Authentication problems
- Malformed messages
- Email sending limits
Let’s briefly go over each of these problems.
Internet Connection Issues
Why aren’t my emails being sent? First, you need to check if your internet connection is working. Yes, it’s basic, but most apps and email clients will allow you to compose a message while offline without providing immediate notifications about the lack of network connection.
Email Server Problems
Why can't I send emails? There might be an issue with your email server, even if the connection is ok. Such problems are usually temporary, but you won’t know it right away, so you’ll need to manually check the platform’s status.
Incorrect SMTP Settings
Why is email not sending? Sometimes, it’s a purely technical problem associated with the specific settings of your email client or the service you’re using to send your emails. These usually show up when you try to send an email for the first time or after reinstalling a client app.
Authentication Problems
Why won’t my emails be sent? It could be simple authorization errors, caused by incorrect username or password. Occasionally your mail account can be blocked by the mail server’s administrator for whatever reason.
Email sending limits
Why is my email not sending? Email servers and external ESPs may impose limits on the number or frequency of emails sent, which could also be a reason for such issues.
Malformed messages
Why did my email fail to send? If you are using a script or an in-house app to send your emails, it may contain errors that result in a message being composed the wrong way. If an email does not adhere to the standards, it will be rejected by your SMTP server.
Recipient Issues
These won’t lead to email sending problems! Recipient-side issues of any kind, including spamblocks, bounces, or wrong target addresses, never result in “Cannot send email” message, so you do not need to worry about them (yet).
Spam Filter Interference
This cause of emails failing to be sent also appears on the list, though it usually relates to email bounces. Still, your SMTP server may have a spam filter enabled for outgoing mail as well, so it’s wise to check for this possibility.
How to Fix Email Not Sending: Step-by-Step Solutions
Stop wondering why emails are not sending — take action! Here are a few ways to help you resolve issues when sending your email:
- Check your internet connection
- Verify mail server status
- Verify your SMTP configuration
- Perform authentication troubleshooting
Let’s dive a bit deeper into each method to solve the email sending problem.
Check Internet Connection
It may sound trivial, but first check if you have internet access. Look at your router indicators and try opening another website through your browser. If there is no connection, reach out to your provider to fix the issue. If the connection is working, proceed with troubleshooting the problem.
Verify Server Status
Your email service provider could also be the reason behind this issue. Try checking the mail host’s availability using free tools like check-host.net. The mail host name can be found among your mail app’s SMTP settings. If it's unreachable, get in touch with technical support or wait for the scheduled maintenance to be completed.
Verify Email Settings
If you have just installed or upgraded your email client, you need to set the correct values for SMTP server settings, most importantly the mail host name and port number. Wrong values will result in email sending failures. In certain cases, you may need to specify additional parameters, such as encryption protocol or character encoding. Ask your network administrator or ESP support for correct values.
Authentication Troubleshooting
An SMTP server usually requires sender verification, which may also be the reason why you cannot send email. The server asks for identification data like the username and password of the email account being used to send the message. If the values you’ve entered in your app’s settings don't match the account information, it will cause a failure. Check the details and correct them if necessary.
ESP-Related Email Sending Issues
The solutions mentioned above mostly apply to problems with desktop email client software. However, for marketing campaigns, you will typically use an Email Service Provider (ESP), accessible via API. This means the issue could be on the client side (your email marketing application), or on the service provider’s side. Therefore, a slightly different approach is required. In such cases, follow these steps:
- Check your app’s settings according to the ESP’s documentation.
- Make sure your account has not been blocked or suspended.
- Verify that your app has not been recently modified or upgraded.
- Reach out to the support team of the service you are using.
The last step may be problematic with some providers due to limited support options. Luckily, with UniOne, you always have access to 24/7 live support chat.
Conclusion
The problem with sending emails can arise due to various reasons. Luckily, you can identify and resolve them on your own with minimal technical knowledge, using the tips from this article.
However, in many cases, you will still need assistance, such as from the technical support team of your email service provider.
UniOne offers not only a convenient and automated toolset with a free trial period, but also full 24/7 technical support in resolving issues related to sending marketing and transactional emails.
Ready to kickstart your email campaigns without unnecessary problems? Try the UniOne service!
FAQ
Why do my emails fail when sending attachments?
The cause of the problem usually relates to your mail server’s or ESP’s limitations. Some allow sending large files as attachments, but in most cases, no more than 25 MB per email is allowed. Providers may also prohibit some types of attachments, such as scripts and executable files, regardless of their size.
What are the common email sending limits?
Free mailbox providers set strict limits on the number of outgoing emails. For example, with Gmail, you can send no more than 100 emails per day via SMTP, or a maximum of 500 using the browser-based client. For larger volumes, you’ll have to purchase a business account or use an ESP like UniOne.
Does the recipient's email provider play any role in sending issues?
The recipient’s mailbox provider can block incoming messages for different reasons. However, this does not manifest as email sending issues, as it is not directly related to the sender's side.
