AOL.com suggests that previous verizon customers change their account settings but I don't see that anything has changed. Can you confirm?

Confirm what? You haven't provided any details about what AOL wants you to change. If in doubt, check with AOL/Verizon. The message is from them after all.

This is what AOL are talking about.

Please add the troubleshooting information to your post, or the Mail and News accounts part of it so we can see your current account settings. To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

Application Basics

   Name: Thunderbird
   Version: 52.3.0
   User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.3.0
   Profile Folder: Show in Finder
   Application Build ID: 20170815040357
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory
   Profiles: about:profiles

 Mail and News Accounts
   account1:
     INCOMING: account1, , (none) Local Folders, plain, passwordCleartext

   account2:
     INCOMING: account2, , (pop3) pop.verizon.net:995, SSL, passwordCleartext
     OUTGOING: , smtp.verizon.net:465, SSL, passwordCleartext, true

   account4:
     INCOMING: account4, , (im) prpl-gtalk, plain, 0

   account5:
     INCOMING: account5, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

 Crash Reports
   https://crash-stats.mozilla.com/report/index/bp-b7b15df1-fd94-457d-a9e7-675372120217 (2/17/12)
   https://crash-stats.mozilla.com/report/index/bp-6204377a-2fbc-4c5d-a566-eff062120217 (2/17/12)
   https://crash-stats.mozilla.com/report/index/bp-401c0e84-6e04-4bc4-8e27-651232120128 (1/28/12)

 Extensions
   Lightning, 5.4.3, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}
   Theme Font & Size Changer, 55.2, true, {f69e22c7-bc50-414a-9269-0f5c344cd94c}

 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
     extensions.lastAppVersion: 52.3.0
     font.internaluseonly.changed: true
     font.minimum-size.x-western: 14
     font.name.sans-serif.x-western: Verdana
     font.name.serif.x-western: Georgia
     font.size.fixed.x-western: 14
     font.size.variable.x-western: 18
     mail.openMessageBehavior.version: 1
     mail.spotlight.enable: true
     mail.spotlight.firstRunDone: true
     mail.spotlight.global_reindex_time: 1419610876
     mailnews.database.global.datastore.id: 96a378c4-8f95-1a49-9d91-321074c5658
     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…
     media.gmp.storage.version.observed: 1
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1506556125
     places.history.expiration.transient_current_max_pages: 63606
     plugin.importedState: true
     print.macosx.pagesetup-2: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPCFET0NUWVBFIHBsaXN0IFBVQkxJQyAiLS8vQXBwbGUvL0RURCBQTElTVCAxLjAvL0VO…
     print.print_bgcolor: false
     print.print_bgimages: false
     print.print_colorspace:
     print.print_command:
     print.print_downloadfonts: true
     print.print_duplex: 0
     print.print_evenpages: true
     print.print_in_color: true
     print.print_margin_bottom: 0.5
     print.print_margin_left: 0.5
     print.print_margin_right: 0.5
     print.print_margin_top: 0.5
     print.print_oddpages: true
     print.print_orientation: 0
     print.print_page_delay: 50
     print.print_pagedelay: 500
     print.print_paper_data: 0
     print.print_paper_height: 11.00
     print.print_paper_name:
     print.print_paper_size: 1084933890
     print.print_paper_size_type: 1
     print.print_paper_size_unit: 0
     print.print_paper_width: 8.50
     print.print_plex_name:
     print.print_printer:
     print.print_resolution: 0
     print.print_resolution_name:
     print.print_reversed: false
     print.print_scaling: 1.00
     print.print_shrink_to_fit: true
     print.print_to_file: false
     print.print_unwriteable_margin_bottom: 56
     print.print_unwriteable_margin_left: 25
     print.print_unwriteable_margin_right: 25
     print.print_unwriteable_margin_top: 25
     privacy.donottrackheader.enabled: true
     security.disable_button.openCertManager: false
     security.disable_button.openDeviceManager: false
     security.OCSP.disable_button.managecrl: false
     security.sandbox.content.tempDirSuffix: {5d4e7162-6f12-7542-965d-835e8e190004}

 Graphics

     GPU #1
     Vendor ID: 0x8086
     Device ID: 0x0116

     Features
     WebGL Renderer: ATI Technologies Inc. -- AMD Radeon HD 6750M OpenGL Engine -- 2.1 ATI-1.51.8

     AzureCanvasBackend: skia
     AzureCanvasAccelerated: 0
     AzureFallbackCanvasBackend: none
     AzureContentBackend: skia
     TileHeight: 512
     TileWidth: 512

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.13.1
     4.13.1

     NSS
     3.28.5
     3.28.5

     NSS Util
     3.28.5
     3.28.5

     NSS SSL
     3.28.5
     3.28.5

     NSS S/MIME
     3.28.5
     3.28.5Matt said

This is what AOL are talking about. Please add the troubleshooting information to your post, or the Mail and News accounts part of it so we can see your current account settings. To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

If your current settings work, just keep them.