"All of the options that are available do not work."

You mean they are greyed out?

Hi igorok2, No, sorry for not being clearer.

Actually I now realize I'm using the wrong terminology. On Thunderbird I have set my "Connection Security" to none and I have tried selecting each of the 5 settings of "Authentication method":

No authentication Password, transmitted insecurely Encrypted password Kerberos / GSSAPI NTLM

but none of them work. So I've tried selecting each of the Authentication model options and tried sending an email and still got the same error.

Short answer: I don't know.

Longer answer: I googled "Syntactically invalid EHLO" (limited to just the past year) and I see people posting about this issue apart even w/o mention of the Thunderbird e-mail client, so whatever your problem there is, it may not be TB-specific.

Is the e-mail server yours, or a company server? My e-mail is on hosted servers and when I have connection issues I check with tech support at my webhost.

Are you using the same port-number settings for your phone and your PC?

It's a company server. I'll have the check with them, because everything, port numbers included, is exactly the same between the two aside from the "Authentication method"

Thanks for your help igorok! If I locate the problem or find the solution I'll post back again...

In Thunderbird Help > Toubleshooting Information click on 'Copy text to clipboard' paste info into this question in the forum.

You can edit/remove all the info on fonts and printers , but please do not edit anything else.

Hi Toad-Hall, thanks for offering to help. Here's the text below. Please let me know if you think this could be a Thunderbird issue, or more likely with my host...

Best, Nick

 Application Basics

   Name: Thunderbird
   Version: 31.6.0
   User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:31.0) Gecko/20100101 Thunderbird/31.6.0
   Profile Folder: Show in Finder
   Application Build ID: 20150330093429
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (imap) hnht-6bph.accessdomain.com:143, plain, passwordCleartext
     OUTGOING: hnht-6bph.accessdomain.com:587, plain, passwordCleartext, true

   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account3:
     INCOMING: account3, , (imap) hp87.hostpapa.com:993, SSL, passwordCleartext
     OUTGOING: hp87.hostpapa.com:465, SSL, passwordCleartext, true

   account5:
     INCOMING: account5, , (imap) imap.googlemail.com:993, SSL, passwordCleartext
     OUTGOING: smtp.googlemail.com:465, SSL, passwordCleartext, true

   account6:
     INCOMING: account6, , (im) prpl-gtalk, plain, 0

 Crash Reports

 Extensions
   gContactSync, 2.0.4, true, gContactSync@pirules.net
   Lightning, 3.3.3, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
   Manually sort folders, 1.1, true, tbsortfolders@xulforum.org
   Provider for Google Calendar, 1.0.4, true, {a62ef8ec-5fdc-40c2-873c-223b8a6925cc}
   S3.Google Translator, 4.02, true, s3google@translator
   Mark Read On Reply and Reply-All, 2.1, false, copiedfrommarkreadonreply@aimcosoftware.co.uk

 Important Modified Preferences

   Name: Value

     accessibility.typeaheadfind.flashBar: 0
     browser.cache.disk.capacity: 358400
     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
     extensions.lastAppVersion: 31.6.0
     font.internaluseonly.changed: true
     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: Calibri
     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
     font.size.variable.x-western: 17
     gfx.direct3d.last_used_feature_level_idx: 1
     mail.openMessageBehavior.version: 1
     mail.spotlight.firstRunDone: true
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: ecc20ba1-ea64-2846-9e03-19fcbea83da
     mailnews.database.global.views.conversation.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     mailnews.database.global.views.global.columns: {"threadCol":{"visible":true,"ordinal":"1"},"flaggedCol":{"visible":true,"ordinal":"3"},"attachmentCol":{"visible":false…
     network.cookie.prefsMigrated: true
     places.database.lastMaintenance: 1429703534
     places.history.expiration.transient_current_max_pages: 104858
     plugin.importedState: true

 Graphics

     Vendor ID: 0x10de
     Device ID: 0x 863
     WebGL Renderer: false
     GPU Accelerated Windows: 2/2 OpenGL

     AzureCanvasBackend: quartz
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: none
     AzureContentBackend: quartz

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.10.6
     4.10.6

     NSS
     3.16.2.3 Basic ECC
     3.16.2.3 Basic ECC

     NSS Util
     3.16.2.3
     3.16.2.3

     NSS SSL
     3.16.2.3 Basic ECC
     3.16.2.3 Basic ECC

     NSS S/MIME
     3.16.2.3 Basic ECC
     3.16.2.3 Basic ECC

Are you talking about account6 ?

    INCOMING: account6, , (im) prpl-gtalk, plain, 0

If no, please provide the following which you are trying to use: Incoming server name: ? incoming port: ? connection security : ? authentication method: ?

outgoing smtp server name: ? outgoing port: ? connection security: ? authentication method: ?

Note; Username = full email address password will be the same one you use to access the webmail account.

Hi Toad-Hall,

No, sorry, I've never looked at one of those things before so I didn't realize what I should have mentioned. The problem is happening with account 1:

  account1:
    INCOMING: account1, , (imap) hnht-6bph.accessdomain.com:143, plain, passwordCleartext
    OUTGOING: hnht-6bph.accessdomain.com:587, plain, passwordCleartext, true

I notice that you are using a MAC. error message "Syntactically invalid EHLO argument(s)".

I presume you tried this on outgoing smtp server: Port: 465 connection Security: SSL/TLS Authentication method: Normal Password

The error message means it did not even get past connection.

I located some information which may assist you. Under section: Connecting

• http://kb.mozillazine.org/Connection_errors_-_SMTP

Then read info at this link:

• http://forums.mozillazine.org/viewtopic.php?t=639883#3303828