![Thunderbird logo](https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/products/2024-02-12-07-36-53-599028_1.png)
Why am I suddenly getting my outgoing email blocked with the message: "The mail server responded: 5.7.1 Spam detected by content scanner."?
This is the second time it's happening, and both times on an email thread that's had several emails go out before. Don't know what server is doing the blocking, because when I go to my web-based email server's (Optimum) interface the email goes through. Just won't go out from Thunderbird.
All Replies (9)
The error message is from your email provider's server. You'll need to ask them why they classify your message as spam.
You may have missed my description. My email provider, Optimum, has no problem when I send the same email reply through their web-based client.
I haven't missed your description. Webmail is entirely different than sending mail via SMTP.
christ1 said
I haven't missed your description. Webmail is entirely different than sending mail via SMTP.
Still following up on this. It's gotten more bizarre. Thunderbird is definitely somehow involved, as I now also see the same basic issue when I send email from my gmail account to an optimum email address. In this case the mail does go out but bounces back with the same error. In summary, any email I send from my optimum address or to an optimum address using TB triggers their spam blocker, but not when sent from webmail clients. Optimum tech support has finally understood me and has escalated its investigation (still waiting). Wondering if someone here has any thoughts on what TB may be contributing to the spam triggering.
Please post your Troubleshooting Information.
At the top right of the Thunderbird window, click the menu button , then select Help > Troubleshooting Information.
Press the Copy text to clipboard button and paste the information into your reply.
Thanks very much for your willingness to look into it. Here's the info (went over the character limit, so I removed all the printer-related lines):
Application Basics
Name: Thunderbird Version: 45.6.0 User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 Profile Folder: Show Folder
(Local drive) Application Build ID: 20161222195647 Enabled Plugins: about:plugins Build Configuration: about:buildconfig Memory Use: about:memory
Mail and News Accounts account1: INCOMING: account1, , (pop3) mail.optimum.net:110, plain, passwordCleartext OUTGOING: , mail.optimum.net:25, plain, passwordCleartext, true
account2: INCOMING: account2, , (none) Local Folders, plain, passwordCleartext
account3: INCOMING: account3, , (pop3) mail.dumka.org:110, plain, passwordCleartext OUTGOING: , host285.hostmonster.com:465, plain, passwordCleartext, true
account6: INCOMING: account6, , (pop3) host285.hostmonster.com:995, SSL, passwordCleartext OUTGOING: , host285.hostmonster.com:465, plain, passwordCleartext, true
account8: INCOMING: account8, , (pop3) mail.optimum.net:110, plain, passwordCleartext OUTGOING: , mail.optimum.net:587, plain, passwordCleartext, true
account11: INCOMING: account11, , (pop3) pop.googlemail.com:995, SSL, passwordCleartext OUTGOING: , smtp.googlemail.com:465, SSL, passwordCleartext, true
account12: INCOMING: account12, , (pop3) mail.optimum.net:110, plain, passwordCleartext OUTGOING: , mail.optimum.net:587, plain, passwordCleartext, true
Crash Reports
Extensions Lightning, 4.7.6, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
Important Modified Preferences
Name: Value
accessibility.typeaheadfind.flashBar: 0 browser.cache.disk.capacity: 358400 browser.cache.disk.filesystem_reported: 1 browser.cache.disk.smart_size_cached_value: 358400 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.display.background_color: #FFFFCC browser.display.foreground_color: #663366 browser.display.screen_resolution: 96 dom.apps.reset-permissions: true extensions.lastAppVersion: 45.6.0 font.internaluseonly.changed: true font.minimum-size.x-western: 14 font.name.monospace.el: Consolas font.name.monospace.tr: Consolas font.name.monospace.x-baltic: Consolas font.name.monospace.x-central-euro: Consolas font.name.monospace.x-cyrillic: Consolas font.name.monospace.x-unicode: Consolas font.name.monospace.x-western: Consolas font.name.sans-serif.el: Calibri font.name.sans-serif.tr: Calibri font.name.sans-serif.x-baltic: Calibri font.name.sans-serif.x-central-euro: Calibri font.name.sans-serif.x-cyrillic: Calibri font.name.sans-serif.x-unicode: Calibri font.name.sans-serif.x-western: Century Gothic font.name.serif.el: Cambria font.name.serif.tr: Cambria font.name.serif.x-baltic: Cambria font.name.serif.x-central-euro: Cambria font.name.serif.x-cyrillic: Cambria font.name.serif.x-unicode: Cambria font.name.serif.x-western: Cambria font.size.fixed.el: 14 font.size.fixed.tr: 14 font.size.fixed.x-baltic: 14 font.size.fixed.x-central-euro: 14 font.size.fixed.x-cyrillic: 14 font.size.fixed.x-unicode: 14 font.size.fixed.x-western: 14 font.size.variable.el: 17 font.size.variable.tr: 17 font.size.variable.x-baltic: 17 font.size.variable.x-central-euro: 17 font.size.variable.x-cyrillic: 17 font.size.variable.x-unicode: 17 gfx.crash-guard.glcontext.appVersion: 45.5.1 gfx.crash-guard.glcontext.deviceID: 0x06e4 gfx.crash-guard.glcontext.driverVersion: 9.18.13.4195 gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle: true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle: true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11: false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp: false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11: true gfx.crash-guard.status.glcontext: 2 gfx.direct3d.last_used_feature_level_idx: 1 mail.openMessageBehavior.version: 1 mail.winsearch.firstRunDone: true mailnews.database.global.datastore.id: c271bd16-05e3-4d53-9c35-b2525790791 mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"21"},"attachmentCol":{"visible":fals… network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1483047334 places.history.expiration.transient_current_max_pages: 104858 places.history.expiration.transient_optimal_database_size: 167772160 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true print.print_printer: Adobe PDF
OUTGOING: , mail.optimum.net:25, plain, passwordCleartext, true
Some email providers block port 25 to prevent spammers from using it. Check with your email provider about the required settings for the outgoing server.
From their web site at https://support.mozilla.org/en-US/questions/1152031 :
SMTP (Outgoing) Server: mail.optimum.net Port: 587 Check 'My SMTP server requires authentication'
They neglected to mention anything about 'Connection security', so I'd first try 'StartTLS'. If that doesn't work try 'none'.
To get to the Account Settings:
At the top right of the Thunderbird window, click the menu button > Options > Account Settings
Adjust the settings for the Outgoing Server (SMTP) at the bottom of the left pane.
In any case, the hero's at optimum.net should explain that to you.
An gyara
Thanks for your suggestions. Tried following them, but don't see an item 'My SMTP server requires authentication' that you mention. Attached is a screen shot of the choices in my SMTP settings window. I've tried several combination and either the same error or different ones, like "encryption not supported" when I tried that. Nothing's changed in those settings in years, BTW. I'll probably just have to wait and see what the optimum folks come up with. But your efforts are very much appreciated.
"Normal password" means authentication. The warning about encryption suggests that you should change STARTTLS to "none".