I google "Mail server sent an incorrect greeting" and I find lots of information that seems relevant, some includes Thunderbird specific information. There is one on groups dot google dot com with this exact error code and referring to vadesecure, so I suspect it is their problem. It could be temporary. As the Server is sending this error it may well be something at the mail provider's server end that has failed or changed. Even if you need to change Thunderbird settings to match their server, you need to know what the server requires first.

Thanks, Agnes RM. I have contacted vadesecure but have not heard back yet. I have contacted earthlink but they say it's not their problem; all my Thunderbird settings are correct. I will try to get onto groups dot google dot com. I'm a bit of a novice at this stuff.

Earthlink are sub contracting with this vadesecure mob to supply email services or at least malware detection. that the system appears to be broken is apparent by the ongoing reports here that it does not work.

Unfortunately I think this is an issue between the two contracted entities. As an earthlink customer it is really up to them to explain how their system works.

my guess is they require a startTLS connection for sending mail, and the mail exchanger registered is the vadesecure server. I will almost bet that the SSL certificate used for starttls is not for the named server and is quietly dying due to that misconfiguration.

Open error console (ctrl+Shift+J) and clear it by clicking on the trash can. Now try and send the mail. Is there some form of error about certificate or cyphers generated?

Matt,

Thanks so much for your detailed reply. Unfortunately, I am not very tech savvy and didn't grasp a lot of it. I will, however, share your idea with Earthlink (if they ever call back!).

I was able to clear the error console and tried to send an email. It would not Send; just got the same error message as I initially reported.

If it's any help, I copied the error messages in the error console and pasted them below.

Diane

1630113998892 addons.xpi-utils WARN addMetadata: Add-on twitter@search.mozilla.org is invalid: Error: File resource://search-extensions/twitter/ does not contain a valid manifest(resource://gre/modules/addons/XPIInstall.jsm:671:11) JS Stack trace: loadManifest@XPIInstall.jsm:671:11 awaitPromise@XPIProvider.jsm:228:15 syncLoadManifest@XPIInstall.jsm:749:24 addMetadata@XPIDatabase.jsm:2810:32 processFileChanges@XPIDatabase.jsm:3254:26 checkForChanges@XPIProvider.jsm:2996:55 startup@XPIProvider.jsm:2456:12 callProvider@AddonManager.jsm:212:31 _startProvider@AddonManager.jsm:583:17 startup@AddonManager.jsm:807:14 startup@AddonManager.jsm:3459:26 observe@addonManager.js:87:29 1630113998893 addons.xpi-utils WARN Not uninstalling invalid item because it is a proxy file 1630113998896 addons.xpi-utils WARN addMetadata: Add-on {972ce4c6-7e08-4474-a285-3208198ce6fd} is invalid: Error: File C:\Program Files (x86)\Mozilla Thunderbird\extensions\{972ce4c6-7e08-4474-a285-3208198ce6fd} does not contain a valid manifest(resource://gre/modules/addons/XPIInstall.jsm:671:11) JS Stack trace: loadManifest@XPIInstall.jsm:671:11 awaitPromise@XPIProvider.jsm:228:15 syncLoadManifest@XPIInstall.jsm:754:22 addMetadata@XPIDatabase.jsm:2810:32 processFileChanges@XPIDatabase.jsm:3254:26 checkForChanges@XPIProvider.jsm:2996:55 startup@XPIProvider.jsm:2456:12 callProvider@AddonManager.jsm:212:31 _startProvider@AddonManager.jsm:583:17 startup@AddonManager.jsm:807:14 startup@AddonManager.jsm:3459:26 observe@addonManager.js:87:29 1630113998896 addons.xpi-utils WARN Could not uninstall invalid item from locked install location Error: Cannot find loader for bootstrap XPIProvider.jsm:1887:15 Error while loading 'jar:file:///C:/Program%20Files%20(x86)/Mozilla%20Thunderbird/omni.ja!/chrome/messenger/search-extensions/twitter/manifest.json' (NS_ERROR_FILE_NOT_FOUND) Extension.jsm:570 1630113999372 addons.xpi WARN Exception running bootstrap method startup on twitter@search.mozilla.org: Error: Error while loading 'jar:file:///C:/Program%20Files%20(x86)/Mozilla%20Thunderbird/omni.ja!/chrome/messenger/search-extensions/twitter/manifest.json' (NS_ERROR_FILE_NOT_FOUND)(resource://gre/modules/Extension.jsm:570:20) JS Stack trace: readJSON/</<@Extension.jsm:570:20 onStopRequest@NetUtil.jsm:128:18 [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 Successfully loaded OpenPGP library rnp.dll version 0.14+git20210121.7c8492b4.MZLA from C:\Program Files (x86)\Mozilla Thunderbird\rnp.dll RNPLib.jsm:95:15 [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 [l10nregistry] Attempting to synchronously load file <pre> resource:///chrome/en-US/locale/en-US/calendar/messenger/openpgp/msgReadStatus.ftl while it's being loaded asynchronously. L10nRegistry.jsm:563:19

[Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 UpdateUtils.getAppUpdateAutoEnabled - Unable to read app update configuration file. Exception: Win error 2 during operation open on file C:\ProgramData\Mozilla\updates\8216C80C92C4E828\update-config.json (The system cannot find the file specified.

) [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 1630114001058 addons.webextension.<unknown> WARN Loading extension 'null': Reading manifest: Warning processing legacy: An unexpected property was found in the WebExtension manifest. Found 0 public keys and 0 secret keys (0 protected, 0 unprotected) RNPLib.jsm:291:15 Trying to load C:\Program Files (x86)\Mozilla Thunderbird\libotr-5.dll OTRLib.jsm:51:11 Successfully loaded OTR library C:\Program Files (x86)\Mozilla Thunderbird\libotr-5.dll OTRLib.jsm:59:13 1630114002974 addons.xpi-utils WARN addMetadata: Add-on twitter@search.mozilla.org is invalid: Error: File resource://search-extensions/twitter/ does not contain a valid manifest(resource://gre/modules/addons/XPIInstall.jsm:671:11) JS Stack trace: loadManifest@XPIInstall.jsm:671:11 awaitPromise@XPIProvider.jsm:228:15 syncLoadManifest@XPIInstall.jsm:749:24 addMetadata@XPIDatabase.jsm:2810:32 processFileChanges@XPIDatabase.jsm:3254:26 getNewSideloads@XPIProvider.jsm:3032:28 1630114002974 addons.xpi-utils WARN Not uninstalling invalid item because it is a proxy file 1630114003143 addons.xpi-utils WARN addMetadata: Add-on {972ce4c6-7e08-4474-a285-3208198ce6fd} is invalid: Error: File C:\Program Files (x86)\Mozilla Thunderbird\extensions\{972ce4c6-7e08-4474-a285-3208198ce6fd} does not contain a valid manifest(resource://gre/modules/addons/XPIInstall.jsm:671:11) JS Stack trace: loadManifest@XPIInstall.jsm:671:11 awaitPromise@XPIProvider.jsm:228:15 syncLoadManifest@XPIInstall.jsm:754:22 addMetadata@XPIDatabase.jsm:2810:32 processFileChanges@XPIDatabase.jsm:3254:26 getNewSideloads@XPIProvider.jsm:3032:28 1630114003143 addons.xpi-utils WARN Could not uninstall invalid item from locked install location 1630114149331 addons.xpi-utils WARN Add-on {58D4392A-842E-11DE-B51A-C7B855D89593} is not compatible with application version. 1630114269468 addons.xpi-utils WARN Add-on {58D4392A-842E-11DE-B51A-C7B855D89593} is not compatible with application version. UpdateUtils.getAppUpdateAutoEnabled - Unable to read app update configuration file. Exception: Win error 2 during operation open on file C:\ProgramData\Mozilla\updates\8216C80C92C4E828\update-config.json (The system cannot find the file specified.

) Some cookies are misusing the recommended “sameSite“ attribute 3 [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 [Exception... "Component returned failure code: 0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH) [nsIXPCComponents_Utils.readUTF8URI]" nsresult: "0x80520001 (NS_ERROR_FILE_UNRECOGNIZED_PATH)" location: "JS frame :: resource://gre/modules/L10nRegistry.jsm :: L10nRegistry.loadSync :: line 658" data: no] L10nRegistry.jsm:658:19 1630256157805 addons.xpi-utils WARN Add-on {58D4392A-842E-11DE-B51A-C7B855D89593} is not compatible with application version. 1630256276391 addons.xpi-utils WARN Add-on {58D4392A-842E-11DE-B51A-C7B855D89593} is not compatible with application version. NS_ERROR_NOT_AVAILABLE UpdateUtils.getAppUpdateAutoEnabled - Unable to read app update configuration file. Exception: Win error 2 during operation open on file C:\ProgramData\Mozilla\updates\8216C80C92C4E828\update-config.json (The system cannot find the file specified.

) NS_ERROR_NOT_AVAILABLE: PreferDisplayName: undefined - not a boolean 2 AddrBookCard.jsm:197