Summary
The user's email bounce issue specifically on their PC but not their mobile device has been attributed to a multitude of possible causes, according to experts, marketers, and documentation. These can be broadly categorized into PC configuration issues (corrupted Outlook profile, incorrect email client settings, incorrect time/date), software interference (browser extensions, plugins injecting hidden text, malware), network problems (firewall blocking, different DNS server, network-specific issues), sender reputation (poor IP reputation), and content-related triggers (spam filtering). Tethering to a mobile network, scanning for malware, testing different email clients, verifying settings, and trying alternate content are suggested troubleshooting steps.
Key findings
- PC Configuration: Issues within the PC's email client configuration, such as corrupted profiles or incorrect settings, could be the root cause.
- Software Interference: Plugins and browser extensions might be interfering with email composition or transmission.
- Network Problems: The PC's network configuration (firewall, DNS) could be blocking or misdirecting email traffic.
- Sender Reputation: The PC's IP address could have a poor reputation, leading to blacklisting.
- Content Filtering: Email content might be triggering spam filters due to keywords, formatting, or hidden text.
- Malware: Malware on the PC could be interfering with email sending or altering settings.
Key considerations
- Tether to Mobile: Test sending emails while tethered to the mobile network to rule out PC network issues.
- Run Malware Scan: Perform a thorough malware scan of the PC.
- Check PC Firewall: Verify that the PC's firewall is not blocking email traffic.
- Review Email Settings: Confirm that email client settings (SMTP, port, etc.) are correctly configured.
- Disable Plugins/Extensions: Temporarily disable plugins and browser extensions to identify potential conflicts.
- Test Different Clients: Try sending emails using different email clients on the PC.
- Create New Profile: Create a new email profile within the email client.
- Check Time and Date: Verify the PC's time and date settings are accurate.
- Test Neutral Content: Send a test email with plain, neutral content to rule out content filtering.
- Review DNS Settings: The PC might be using a different DNS server than the mobile device.
What email marketers say
9 marketer opinions
The user is experiencing email bounces when sending from their PC but not from their mobile device. This issue could stem from a variety of factors related to the PC's configuration, network, or security. Several suggestions point towards potential PC-specific problems such as IP address blocking, malware, firewall settings, incorrect email client settings, problematic browser extensions, incorrect system time, and differing DNS settings. Others suggest the content being sent from the PC may be triggering spam filters, or the email client itself is compromised. It is also worth considering general sender reputation issues.
Key opinions
- IP Blocking: The PC's IP address might be blocked by the recipient's email server or firewall.
- Malware: Malware on the PC could be injecting unwanted content or altering email settings.
- Firewall: Firewall settings on the PC might be blocking email traffic or specific ports.
- Client Settings: Incorrect email client settings on the PC (SMTP, port numbers) could cause issues.
- Content Filtering: Email content sent from the PC might be triggering spam filters.
- Network Issues: Network-specific issues on the PC's connection may be causing problems.
- Time/Date: An incorrect time/date setting on the PC might cause SSL/TLS certificate issues.
- IP reputation: PC may have a poor IP reputation
Key considerations
- Network Test: Try tethering the PC to the phone's mobile data to rule out network-specific issues.
- Malware Scan: Run a thorough malware scan on the PC.
- Firewall Check: Review and adjust the PC's firewall settings to ensure email traffic isn't blocked.
- Email Client Test: Test with different email clients on the PC to isolate the problem.
- Time/Date Verification: Confirm the PC's time and date settings are accurate.
- Review Content: Examine the email content being sent from the PC for potential spam triggers.
- Review DNS Settings: The PC might be using a different DNS server than the mobile device.
Marketer view
Marketer from Email Geeks suggests tethering the laptop to the phone, using the phone's service to send the email from the PC to see if the same bounce occurs.
11 Aug 2024 - Email Geeks
Marketer view
Email marketer from Email Marketing Forum suggests testing with different email clients (e.g., Thunderbird, Outlook) on the PC to determine if the issue is specific to one client.
26 Dec 2023 - Email Marketing Forum
What the experts say
6 expert opinions
The user is experiencing email bounces when sending from their PC but not their mobile device. Experts suggest that the problem could be related to several PC-specific factors. These include plugins injecting hidden text, malware interference, a poor IP reputation leading to blacklisting, or the content being filtered by overly zealous guard rails on new accounts/domains. A neutral content test and checking for malware are recommended. Testing from Hotmail is also suggested.
Key opinions
- Plugin Interference: Plugins like Grammarly might be injecting hidden text into emails.
- Content Filtering: Email content might be flagged by spam filters, especially for new accounts/domains.
- PC Malware: Malware on the PC could be interfering with email sending.
- IP Reputation: The PC's IP address might have a poor reputation due to past spam activity.
Key considerations
- Disable Plugins: Disable plugins to see if they are causing the issue.
- Test Neutral Content: Send emails with neutral content to rule out content filtering issues.
- Run Malware Scan: Perform a thorough malware scan on the PC.
- Test with Hotmail: Send emails from Hotmail to check if the issue persists.
- Account Age: Consider if the email account or domain is new, as this can trigger stricter filtering.
Expert view
Expert from Spam Resource suggests that the PC's IP address might have developed a poor reputation due to past spam activity or blacklisting, leading to email bounces. The mobile device, using a different network, wouldn't be affected by this.
30 May 2025 - Spam Resource
Expert view
Expert from Word to the Wise suggests that it is possible that the computer has malware running in the background which is interfering with email sending. This could be because it has been compromised.
14 Aug 2022 - Word to the Wise
What the documentation says
5 technical articles
The user's email bounce issue specifically on their PC, but not mobile, could be due to several factors documented by various support resources. These include a corrupted Outlook profile, interfering browser extensions in Gmail, network or server connection issues diagnosable via Mail Connection Doctor (macOS), different DNS server settings compared to the mobile device, and a poor IP reputation for the PC's sending IP address.
Key findings
- Corrupted Outlook Profile: A corrupted Outlook profile on the PC could be the cause.
- Browser Extension Interference: Browser extensions in Gmail may be interfering with email sending.
- Network/Server Issues (macOS): Network or server connection problems within the Mail application on macOS may exist.
- Different DNS Servers: The PC might be using a different DNS server than the mobile device.
- Poor IP Reputation: The PC's sending IP address might have a poor reputation.
Key considerations
- Create New Outlook Profile: Create a new Outlook profile to test if the issue persists (if applicable).
- Disable Browser Extensions: Disable browser extensions one by one to identify the problematic one (if using Gmail web).
- Run Mail Connection Doctor: Use Mail Connection Doctor on macOS to diagnose network issues (if applicable).
- Check DNS Settings: Verify and potentially change the DNS settings on the PC.
- Address IP Reputation: Take steps to improve the PC's IP reputation (if it's the root cause).
Technical article
Documentation from Apple Support recommends using Mail Connection Doctor to diagnose network and server connection problems within the Mail application on macOS.
12 May 2024 - Apple Support
Technical article
Documentation from Postmark states the sending IP reputation of the user's PC could be negatively impacting email delivery. Whereas the mobile app may be routing email via a different mechanism that has better IP reputation.
28 May 2022 - Postmark Documentation
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