Thunderbird can't connect to a specific IMAP server
On 5th of October Thunderbird updated to 102.3.1. After that update Thunderbird was no longer able to login to my Mailserver (IMPA) the connection was working fine before and is setup to use TLS/SSL. In fact there seems to be a problem with the server-certificate as I see in the log of the server the following error: imap-login: Disconnected (no auth attempts in 1 secs): user=<>, rip=XX.XXX.XXX.XXX, lip=XX.XXX.XXX.XXX, TLS: SSL_read() failed: error:14094412:SSL routines:SSL3_READ_BYTES:sslv3 alert bad certificate: SSL alert number 42, session=<6v82lm/qpABQj4+n> I do not know what exactly is the problem; but in fact I do have an exception setup for the server certificate. For me it seems that this server certificate exception is no longer considered after the update; but am not sure.
Could someone please assist me on how to solve this issue?
Thanks in advance.
All Replies (7)
Do you still get the certificate exception prompt? What is the error code? Please post a screenshot. https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem
sslv3 alert bad certificate: SSL alert number 42
Receiving alert bad certificate (code 42) means the server demands you authenticate with a certificate.
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.
Modified by christ1
Hi Christ1!
No I do not get the certificate exception prompt. TB is just trying to connect and after a long time I get a timeout message.
Here is the output of Help/Troubleshoot-Info:
Allgemeine Informationen
Name: Thunderbird Version: 102.3.1 Build-ID: 20220928170044 Distributions-ID:
Update-Kanal: release User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.3.1 Betriebssystem: Windows_NT 10.0 19043 Betriebssystem-Theme:
Starter-Prozess: Aktiviert
Fenster mit mehreren Prozessen: 0/0
Fission-Fenster: 0/0
Standardmäßig aktiviert
Externe Prozesse: 4
Unternehmensrichtlinien: Aktiv
Google-Location-Service-Schlüssel: Fehlt
Google-Safebrowsing-Schlüssel: Fehlt
Mozilla-Location-Service-Schlüssel: Fehlt
Abgesicherter Modus: false
Speichergröße (RAM): 15,7 GB
Speicherplatz verfügbar: 129 GB
E-Mail- und Newsgruppen-Konten
account1:
INCOMING: account1, , (imap) secure-imap.nuevas.de:993, SSL, passwordCleartext
OUTGOING: , secure-smtp.nuevas.de:465, SSL, passwordCleartext, true
OUTGOING: , secure-smtp.nuevas.de:465, SSL, passwordCleartext, false
OUTGOING: , secure-smtp.nuevas.de:465, SSL, passwordCleartext, false
OUTGOING: , secure-smtp.nuevas.de:465, SSL, passwordCleartext, false
account2:
INCOMING: account2, , (none) Local Folders, 0, passwordCleartext
account3:
INCOMING: account3, , (imap) secureimap.t-online.de:993, SSL, passwordCleartext
OUTGOING: , securesmtp.t-online.de:587, alwaysSTARTTLS, passwordCleartext, true
account5:
INCOMING: account5, , (imap) imap.gmail.com:993, SSL, OAuth2
OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true
account6:
INCOMING: account6, , (imap) secure-imap.nuevas.de:993, SSL, passwordCleartext
OUTGOING: , secure-smtp.nuevas.de:465, SSL, passwordCleartext, true
account7:
INCOMING: account7, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true
account8:
INCOMING: account8, , (imap) imap.web.de:993, SSL, passwordCleartext
OUTGOING: , smtp.web.de:587, alwaysSTARTTLS, passwordCleartext, true
Kalender-Einstellungen
Privat
Name
Wert
Name:
Typ: storage
Deaktiviert:
Benutzername:
URI:
Aktualisierungsintervall:
Schreibgeschützt:
Erinnerungen deaktivieren:
Cache aktiviert:
iMIP-Identität: id1
iMIP deaktiviert:
iMIP-Konto:
Organisator-ID:
Terminmitteilungen per E-Mail senden:
Popup-Erinnerungen unterstützt:
Erinnerungen für Einladung unterstützt:
Maximale Erinnerungen für Termin:
Anhang unterstützt:
Maximale Anzahl an Kategorien:
Privatsphäre-Status unterstützt:
Priorität unterstützt: true
Termin unterstützt:
Aufgabe unterstützt:
Lokale Zeit unterstützt:
UTC/GMT unterstützt:
Automatische Terminmitteilungen unterstützt:
Absturzberichte der letzten 3 Tage
Externe Prozesse
Typ: Anzahl
Webinhalt: 1 / 8
Erweiterung: 1
about-Seite mit zusätzlichen Rechten: 1
GPU: 1
Add-ons
Name
Typ
Version
Aktiviert
ID
Amazon.de extension 1.1 true amazon@search.mozilla.org
Bing
extension
1.0
true
bing@search.mozilla.org
Bitdefender Toolbar
extension
26.0.18.75
true
bdThunderbird78@bitdefender.com
DuckDuckGo
extension
1.0
true
ddg@search.mozilla.org
Ecosia
extension
1.1
true
ecosia@search.mozilla.org
Google
extension
1.0
true
google@search.mozilla.org
ImportExportTools NG
extension
12.0.1
true
ImportExportToolsNG@cleidigh.kokkini.net
LEO Eng-Deu
extension
1.0
true
leo_ende_de@search.mozilla.org
Wikipedia (de)
extension
1.0
true
wikipedia@search.mozilla.org
Sicherheitssoftware
Typ: Name
Antivirus: Bitdefender Virenschutz
Antispyware:
Firewall: Bitdefender Firewall
Grafik
Allgemeine Merkmale
Compositing: WebRender
Asynchrones Wischen und Zoomen: Mausrad-Eingabe aktiviert; Ziehen der Bildlaufleiste aktiviert; Tastatur aktiviert; automatischer Bildlauf aktiviert; sanftes Zoomen durch Antippen aktiviert
WebGL-1-Treiber: WSI Info: EGL_VENDOR: Google Inc. (Intel)
EGL_VERSION: 1.5 (ANGLE 2.1.15727 git hash: 23851a53779d) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_display_semaphore_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_ANDROID_blob_cache EGL_ANDROID_recordable EGL_ANGLE_image_d3d11_texture EGL_ANGLE_create_context_backwards_compatible EGL_KHR_create_context_no_error EGL_KHR_reusable_sync EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_device_query EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_platform_angle_d3d11on12 EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_KHR_debug EGL_ANGLE_explicit_context EGL_ANGLE_feature_control IsWebglOutOfProcessEnabled: 1
WebGL-1-Treiber: Renderer: Google Inc. (Intel) -- ANGLE (Intel, Intel(R) HD Graphics 4600 Direct3D11 vs_5_0 ps_5_0, D3D11-20.19.15.4835)
WebGL-1-Treiber: Version: OpenGL ES 2.0.0 (ANGLE 2.1.15727 git hash: 23851a53779d)
WebGL-1-Treiber: Erweiterungen: GL_ANGLE_base_vertex_base_instance GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_get_serialized_context_string GL_ANGLE_get_tex_level_parameter GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_memory_size GL_ANGLE_multi_draw GL_ANGLE_multiview_multisample GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_provoking_vertex GL_ANGLE_request_extension GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_lose_context GL_CHROMIUM_sync_query GL_EXT_EGL_image_external_wrap_modes GL_EXT_blend_func_extended GL_EXT_blend_minmax GL_EXT_color_buffer_half_float GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_draw_elements_base_vertex GL_EXT_float_blend GL_EXT_frag_depth GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_multisampled_render_to_texture GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_bptc GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_rgtc GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_no_error GL_KHR_parallel_shader_compile GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_compressed_EAC_R11_signed_texture GL_OES_compressed_EAC_R11_unsigned_texture GL_OES_compressed_EAC_RG11_signed_texture GL_OES_compressed_EAC_RG11_unsigned_texture GL_OES_compressed_ETC2_RGB8_texture GL_OES_compressed_ETC2_RGBA8_texture GL_OES_compressed_ETC2_punchthroughA_RGBA8_texture GL_OES_compressed_ETC2_punchthroughA_sRGB8_alpha_texture GL_OES_compressed_ETC2_sRGB8_alpha8_texture GL_OES_compressed_ETC2_sRGB8_texture GL_OES_depth24 GL_OES_depth32 GL_OES_draw_elements_base_vertex GL_OES_element_index_uint GL_OES_fbo_render_mipmap GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_texture_stencil8 GL_OES_vertex_array_object GL_WEBGL_video_texture
WebGL-1-Erweiterungen: ANGLE_instanced_arrays EXT_blend_minmax EXT_color_buffer_half_float EXT_float_blend EXT_frag_depth EXT_shader_texture_lod EXT_sRGB EXT_texture_compression_bptc EXT_texture_compression_rgtc EXT_texture_filter...
Which of the six IMAP accounts does have the problem?
The server secure-imap.nuevas.de only has a self-signed key. So you'd have to obtain the server cert and import it into Thunderbird for this to work without an exception. It may have other problems as well.
Hi Christ1!
Yes it is secure-imap.nuevas.de where I do have the problem. And As I already mentioned on my initial post, the certificate is already added in Thunderbird as exception, see attached image.
Antivirus: Bitdefender Virenschutz Antispyware: Firewall: Bitdefender Firewall
Try to start Windows 10 in safe mode with networking enabled.
Does the problem go away?
Windows safe mode disables anti-virus software. This is a troubleshooting step, not a solution.
Nope! Problem also exists in Save-Mode.
Well, then I'd suggest you contact the email provider about the 'sslv3 alert bad certificate: SSL alert number 42' error.