If you can receive emails but can’t send them, it usually means your internet connection and incoming mail are working, but something is wrong with the outgoing side of your email setup.
This is a common email problem. Messages may sit in the Outbox, fail with an error, ask for your password repeatedly, or appear to send from one device but not another.
The confusing part is that receiving mail and sending mail are often handled by different settings and sometimes even different servers.
That means your inbox can keep working normally while outgoing email fails completely.
If the problem is not limited to this send/receive mismatch, my main emails not sending page covers the broader causes and how I troubleshoot them.
Why Receiving Can Work When Sending Fails
Email apps normally use one set of settings to receive messages and another set to send them.
Incoming mail is usually handled by IMAP or POP. Outgoing mail is usually handled by SMTP.
So when someone says they can receive emails but can’t send, the problem is often not the whole email account. It is usually the outgoing mail path.
That path can fail because of incorrect SMTP settings, authentication problems, port or encryption issues, server restrictions, app problems, or changes made by the email provider.
Common Causes of This Email Sending Problem
- 📤 The outgoing SMTP server is incorrect or no longer accepted by the email provider.
- 🔐 The email app is using the wrong username, password, or authentication method for sending.
- ⚙️ The port or encryption setting is wrong, such as using the wrong SSL, TLS, or STARTTLS option.
- 📱 One device has the correct settings, but another device has old or mismatched settings.
- 🚫 The internet provider, mail host, or security service is blocking or restricting outgoing mail.
- 🧩 Outlook, Apple Mail, Gmail, or another email app has a damaged profile or cached old settings.
SMTP vs IMAP Mismatch
One of the most common causes is a mismatch between incoming and outgoing server settings.
Your incoming IMAP settings may be correct, which is why new emails still arrive. But if the SMTP settings are wrong, outgoing messages will fail.
This can happen after changing passwords, moving email hosting, changing internet providers, setting up a new computer, or copying settings from an older device without checking whether they are still correct.
It is also common with business email accounts where the domain, website hosting, mailbox provider, and DNS records are all managed separately.
Authentication Failures
Some email accounts require separate authentication for outgoing mail.
That means the app cannot simply receive mail and assume it is allowed to send. It may need to log in again using the correct mailbox credentials, modern authentication, or an app-specific password.
This can cause password prompts, repeated send failures, or vague errors that do not clearly explain what is wrong.
For Gmail, Microsoft 365, Outlook.com, and many business email systems, older password methods may no longer work reliably in some apps.
Port and Encryption Problems
Outgoing email usually depends on the correct combination of server name, port number, encryption method, and authentication.
If one of those is wrong, sending can fail even though the account looks mostly correct.
For example, an account may need secure SMTP on a specific port, but the email app may still be trying to send using an older or blocked method.
This is why simply retyping the password often does not fix the issue. The underlying sending configuration may still be wrong.
ISP or Server Restrictions
Sometimes the problem is not the email app itself.
Some internet providers, mail hosts, or security systems restrict certain types of outgoing mail traffic. This can affect older SMTP settings, incorrectly configured business email, or devices that were set up years ago and never updated.
In other cases, the mail server may reject sending because the account is over quota, the domain settings are incomplete, the mailbox has been suspended, or the server thinks the account is at risk.
When this happens, the fix may involve the mail host, domain DNS records, email security settings, or server-side account settings.
Why It Can Work on One Device But Not Another
A very common clue is when email sends from your phone but not your computer, or sends from webmail but not Outlook.
That usually means the mailbox itself is still capable of sending, but one app or device has a local configuration problem.
The opposite can also happen. Your computer may send normally, but your phone fails because it has old saved settings, an expired password, or the wrong outgoing server.
Comparing a working device against a failing one can help identify whether the problem is with the account, the app, the device, or the mail server.
What I Check When Troubleshooting This
- ✅ Whether the account can send from webmail or another known-good device.
- ✅ Whether the outgoing SMTP server, port, encryption, and authentication settings are correct.
- ✅ Whether the password or sign-in method has changed.
- ✅ Whether Outlook, Apple Mail, Gmail, or the phone mail app is using old cached settings.
- ✅ Whether the mail host, domain, or DNS configuration is causing the sending failure.
- ✅ Whether security software, server restrictions, or provider blocks are interfering with outgoing mail.
When It Needs Proper Diagnosis
If you can receive emails but can’t send, guessing can make the problem worse. For help with emails not sending, I can identify whether the issue is with the account, app, device, outgoing server, or email host.
Changing random settings may break receiving as well, remove saved account details, or create duplicate mail profiles.
The better approach is to identify exactly where the send path is failing first. Then the right fix can be applied without disrupting the rest of the email setup.
That might mean correcting SMTP settings, repairing an Outlook profile, updating authentication, checking mail server settings, fixing DNS records, or escalating to the mail host with the right information.
Need Help Fixing an Email Sending Problem?
PcRiot helps home users and small businesses in Perth troubleshoot email problems across Outlook, Gmail, Apple Mail, phone mail apps, business email, domains, and mail hosting.
If your emails are coming in but not going out, I can help identify whether the problem is with the account, app, device, outgoing server, or email host.
Contact PcRiot for help with email sending problems in Perth.