That bug is invalid for a reason.

So how about some information about your set up. Please add the troubleshooting information to your post To find the Troubleshooting information:

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Please also add the result of these troubleshooting steps to your post

• Does Thunderbird work in TB Safe mode (see Thunderbird Safe Mode)?
• Do you use your own mail server? (Hosted/Local)
• Does the server use SSL/TLS encryption certificates issued by Symantec and it's subsidiaries?

MyCat:

Troubleshooting reveals:

Troubleshooting Information

This page contains technical information that might be useful when you're trying to solve a problem. If you are looking for answers to common questions about Thunderbird, check out our support web site. Include account names (possibly identifying information) Application Basics Name Thunderbird Version 60.2.1 Build ID 20181010142617 Update History User Agent Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 OS Linux 4.15.0-39-generic Profile Directory (Local drive) Enabled Plugins about:plugins Build Configuration about:buildconfig Memory Use about:memory Performance about:performance Registered Service Workers about:serviceworkers Multiprocess Windows 0/0 (Disabled) Stylo content = true (enabled by default), chrome = true (enabled by default) Google Key Missing Mozilla Location Service Key Missing Safe Mode false Profiles about:profiles Mail and News Accounts ID Incoming server Outgoing servers Name Connection security Authentication method Name Connection security Authentication method Default? account2 (none) Local Folders None Normal password account3 (imap) mail.thevillages.net:143 STARTTLS Encrypted password mail.thevillages.net:587 STARTTLS Encrypted password true account4 (imap) imap.gmail.com:993 SSL/TLS OAuth2 smtp.gmail.com:465 SSL/TLS OAuth2 true account6 (movemail) localhost None Normal password mail.thevillages.net:587 STARTTLS Encrypted password true Crash Reports for the Last 3 Days Report ID Submitted

All Crash Reports Extensions Name Version Enabled ID Lightning 6.2.2.1 true {e2fda1a4-762b-4020-b5ad-a41df1933103} Messaging Menu and Unity Launcher integration 1.4 true messagingmenu@mozilla.com Saved Password Editor 2.10.3 false savedpasswordeditor@daniel.dawson Graphics Features Compositing Basic Asynchronous Pan/Zoom none WebGL 1 Driver WSI Info GLX 1.4 GLX_VENDOR(client): AMD GLX_VENDOR(server): AMD Extensions: GLX_ARB_create_context GLX_ARB_create_context_profile GLX_ARB_fbconfig_float GLX_ARB_framebuffer_sRGB GLX_ARB_get_proc_address GLX_ARB_multisample GLX_EXT_import_context GLX_EXT_visual_info GLX_EXT_visual_rating GLX_EXT_framebuffer_sRGB GLX_EXT_create_context_es2_profile GLX_MESA_copy_sub_buffer GLX_MESA_swap_control GLX_OML_swap_method GLX_OML_sync_control GLX_SGI_make_current_read GLX_SGI_swap_control GLX_SGI_video_sync GLX_SGIS_multisample GLX_SGIX_fbconfig GLX_SGIX_pbuffer GLX_SGIX_visual_select_group GLX_EXT_texture_from_pixmap GLX_INTEL_swap_event 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GL_ARB_fragment_coord_conventions GL_ARB_fragment_layer_viewport GL_ARB_fragment_program GL_ARB_fragment_program_shadow GL_ARB_fragment_shader GL_ARB_framebuffer_no_attachments GL_ARB_framebuffer_object GL_ARB_framebuffer_sRGB GL_ARB_geometry_shader4 GL_ARB_get_program_binary GL_ARB_get_texture_sub_image GL_ARB_gl_spirv GL_ARB_gpu_shader5 GL_ARB_gpu_shader_fp64 GL_ARB_half_float_pixel GL_ARB_half_float_vertex GL_ARB_imaging GL_ARB_indirect_parameters GL_ARB_instanced_arrays GL_ARB_internalformat_query GL_ARB_internalformat_query2 GL_ARB_invalidate_subdata GL_ARB_map_buffer_alignment GL_ARB_map_buffer_range GL_ARB_multi_bind GL_ARB_multi_draw_indirect GL_ARB_multisample GL_ARB_multitexture GL_ARB_occlusion_query GL_ARB_occlusion_query2 GL_ARB_parallel_shader_compile GL_ARB_pipeline_statistics_query GL_ARB_pixel_buffer_object GL_ARB_point_parameters GL_ARB_point_sprite GL_ARB_program_interface_query GL_ARB_provoking_vertex GL_ARB_query_buffer_object GL_ARB_robust_buffer_access_behavior 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I am using Thunderbird V60.2.1 (64-bit) on both Linux Ubuntu 18.4 and Windows 10, both 64 bit OS's. My modem has been checked by Comcast and is operating normally. Comcast also checked their servers to see if something is blocking my outbound email, but found no problems.

I deleted the Comcast email account in T-bird, but now can not add it as a new account because the "...user name and password do not match with that provider..." Comcast verified that they do indeed match.

I have not tried T-Bird Safe Mode, so no results; later today perhaps. Mail Servers is: imap.comcast.net Inbound and smtp.comcast.net Outbound. I do not have my own. Comcast Servers use SSL/TLS.

I note you mention 'comcast' and Linux. there have been several reports at the moment regarding this.

Sounds like comcast are having some issues.

• https://downdetector.com/status/comcast-xfinity

I did locate info where someone also using Linux got a hint to change the IMAP server name from imap.comcast.net to imap.ge.xfinity.com

• https://forums.xfinity.com/t5/Email-Web-Browsing/Error-The-connection-to-remote-server-imap-email-comcast-net/td-p/3167847

For those looking for a more direct answer, name resolution for imap.comcast.net seems to be failing recently. Users in the Ubuntu forum thread offer the resolution of changing the account's server to one of the IP addresses reported by "nslookup imap.comcast.net" (use the terminal, Luke.) Rather than using a fixed IP address, I reset the server name to imap.ge.xfinity.com (the canonical name for imap.comcast.net) then had to submit my password for the newly-named server. Works a treat.

Try changing the server name and report back on results.

I changed the Comcast Server name to "imap.ge.xfinity.com" and that made it work as advertised. The new account came up in T-Bird and downloaded all the emails on the server.

Thank you!