Apple mail Sierra keeps deleting my SMTP details

I had this problem too. Drove me nuts.

In System Preferences/iCloud turn off keychain syncing and/or iCloud Drive.

I had the same problem, I went into system preferences, Internet accounts and deleted the account i could not access. I then added the account again. It seems to be ok now

I have five email accounts on my mac mail and don't want to lose all the info on all the accounts. I am having problems only with the Yahoo one. How do I do this without deleting all the accounts and all the stored email in my local folders?

When you remove an IMAP account it removes only the IMAP data. If it's POP it removes the Inbox, Drafts, Sent folders. You would need to backup first before deleting. It does not remove any local "On My Mac" folders.

Mine is doing the same. I only have the issue on my iMac and MacBook Pro but not my iPhone or iPad. Anyone know what's going on and how to fix it?

Hello Diane,

Thanks for the step-by-step guide. Unfortunately, my problem seems to be global. What do you suggest/recommend?

Thanks again.

When you tested in the new User, were you synced via iCloud Keychain?

When you installed Sierra did you do this over a previous version of OS X? If yes, what version?

What email provider? Comcast, Earthlink, Cox, ATT, Yahoo, iCloud, Gmail, AOL, Hotmail (other)

Have you booted into the Recovery Drive and run Disk First Aid on your drive?

Boot into the Recovery Drive by holding down Command R when restarting.

Open Disk Utility

Run First Aid on your internal drive, Macintosh HD

Quit Disk Utility

Restart your Mac

Download EtreCheck. (a utility by a respected member of this community) and post its report here, so we have a better idea of your hardware and software setup so we can better help.

http://www.etresoft.com/etrecheck

EtreCheck version: 3.1.2 (334)

Report generated 2016-11-15 21:19:51

Download EtreCheck from https://etrecheck.com

Runtime 8:41

Performance: Below Average

Click the [Support] links for help with non-Apple products.

Click the [Details] links for more information about that line.

Click the [Remove] links to remove adware.

Problem: Other problem

Description:

I cannot send email from either of the two accounts on my machine:

1. An AOL account (IMAP) - this account is unable to connect to the server via SMTP, and at one stage, was deleting the settings. This stopped after deleting the com.apple.mail folder from Containers in the User’s Library. There is also an AOL SMTP option that seems impossible to delete - it appears in the list of Outgoing Mail Accounts in Mail Preferences, but does not show up under the Edit SMTP Server List option.

2. A Personal Setup (POP) - Even though this account connects to the server via SMTP, email sent never arrives.(I do not believe - although I may be wrong - that this issue is related to the AOL problem)

To answer your questions:
1. No, I was not synced via iCloud Keychain

2. Yes, I installed Sierra over El Capitan - this issue did not start with Sierra however. I believe it started under Yosemite.

3. AOL

4. Yes, I did, but it hasn't changed anything for the better - my AOL SMTP has disappeared from Mail Connection Doctor

Hardware Information: ⓘ

iMac (27-inch, Mid 2011)

[Technical Specifications] - [User Guide] - [Warranty & Service]

iMac - model: iMac12,2

1 2.7 GHz Intel Core i5 (i5-2500S) CPU: 4-core

16 GB RAM Upgradeable - [Instructions]

BANK 0/DIMM0

4 GB DDR3 1333 MHz ok

BANK 1/DIMM0

4 GB DDR3 1333 MHz ok

BANK 0/DIMM1

4 GB DDR3 1333 MHz ok

BANK 1/DIMM1

4 GB DDR3 1333 MHz ok

Bluetooth: Old - Handoff/Airdrop2 not supported

Wireless: en1: 802.11 a/b/g/n

Video Information: ⓘ

AMD Radeon HD 6770M - VRAM: 512 MB

iMac 2560 x 1440

System Software: ⓘ

macOS Sierra 10.12.1 (16B2555) - Time since boot: less than an hour

Disk Information: ⓘ

ST31000528AS disk0 : (1 TB) (Rotational)

[Show SMART report]

EFI (disk0s1) <not mounted> : 210 MB

Recovery HD (disk0s3) <not mounted> [Recovery]: 650 MB

Macintosh HD (disk1) / [Startup]: 998.97 GB (300.96 GB free)

Encrypted AES-XTS Unlocked

Core Storage: disk0s2 999.35 GB Online

HL-DT-STDVDRW GA32N ()

USB Information: ⓘ

Apple Computer, Inc. IR Receiver

Apple Card Reader

Apple Inc. FaceTime HD Camera (Built-in)

Seagate Backup+ Desk

Western Digital My Book

JMicron USB to ATA/ATAPI Bridge

Seagate FreeAgent

Apple Inc. BRCM2046 Hub

Apple Inc. Bluetooth USB Host Controller

Thunderbolt Information: ⓘ

Apple Inc. thunderbolt_bus

Promise Technology, Inc. Pegasus R-Series

Configuration files: ⓘ

/etc/sysctl.conf - File exists but not expected

/etc/hosts - Count: 15

Gatekeeper: ⓘ

Mac App Store and identified developers

Adware: ⓘ

~/Library/LaunchAgents/com.extensions.updater69337.ver

One adware file found. [Remove]

Unknown Files: ⓘ

/Library/LaunchDaemons/com.iobit.AMCDaemon.plist

/Library/Application Support/MacBooster/AMCDaemon -load

~/Library/LaunchAgents/com.iobit.AMCUpdate.plist

/Applications/04 Maintenance/MacBooster 3.app/Contents/Resources/AMCUpdate.app/Contents/MacOS/AMCUpdate

2 unknown files found. [Check files]

Kernel Extensions: ⓘ

/Library/Application Support/Roxio

[not loaded] com.roxio.TDIXController (2.0 - 2016-01-27) [Support]

/Library/Extensions

[loaded] at.obdev.nke.LittleSnitch (3.7 - SDK 10.11 - 2016-11-03) [Support]

[loaded] com.promise.driver.stex (5.2.10 - SDK 10.9 - 2016-11-03) [Support]

[not loaded] com.promise.r2p.icon (1.0.7 - SDK 10.11 - 2016-11-03) [Support]

[loaded] net.telestream.driver.TelestreamAudio (1.1.1 - SDK 10.8 - 2016-11-03) [Support]

/System/Library/Extensions

[not loaded] com.Greatdy.driver.SystemAudioCapture (1.0.0 - SDK 10.8 - 2016-11-03) [Support]

[not loaded] com.fsb.kext.logKext (2.3 - 2016-11-03) [Support]

[not loaded] com.rim.driver.BlackBerryUSBDriverVSP (0.0.74 - 2016-11-03) [Support]

[not loaded] com.vara.driver.VaraAudio (1.0.2 - 2016-11-03) [Support]

Startup Items: ⓘ

HDDFanControlDaemon: Path: /Library/StartupItems/HDDFanControlDaemon

Startup items no longer function in OS X Yosemite or later

System Launch Agents: ⓘ

[not loaded] 8 Apple tasks

[loaded] 166 Apple tasks

[running] 97 Apple tasks

System Launch Daemons: ⓘ

[not loaded] 38 Apple tasks

[loaded] 160 Apple tasks

[running] 106 Apple tasks

Launch Agents: ⓘ

[running] at.obdev.LittleSnitchUIAgent.plist (2016-09-24) [Support]

[not loaded] com.adobe.AAM.Updater-1.0.plist (2016-01-24) [Support]

[running] com.avg.Antivirus.gui.plist (2016-11-15) [Support]

[loaded] com.epson.esua.launcher.plist (2016-08-09) [Support]

[running] com.epson.eventmanager.agent.plist (2015-08-13) [Support]

[loaded] com.google.keystone.agent.plist (2016-08-24) [Support]

[loaded] com.hp.help.tocgenerator.plist (2014-08-01) [Support]

[not loaded] com.maintain.PurgeInactiveMemory.plist (2016-10-19)

[not loaded] com.maintain.Restart.plist (2016-09-13)

[not loaded] com.maintain.ShutDown.plist (2016-09-13)

[running] com.maintain.SystemEvents.plist (2016-09-13)

[loaded] com.oracle.java.Java-Updater.plist (2016-10-24) [Support]

[running] com.rim.BBAlbumArtCacher.plist (2012-12-29) [Support]

Launch Daemons: ⓘ

[running] at.obdev.littlesnitchd.plist (2016-09-24) [Support]

[loaded] com.adobe.SwitchBoard.plist (2016-01-24) [Support]

[loaded] com.adobe.fpsaud.plist (2016-10-25) [Support]

[loaded] com.apple.aelwriter.plist (2012-07-08)

[loaded] com.avg.Antivirus.crashpad.plist (2016-09-23) [Support]

[running] com.avg.Antivirus.infosd.plist (2016-09-23) [Support]

[running] com.avg.Antivirus.services.plist (2016-09-23) [Support]

[running] com.disc-soft.DAEMONTools.PrivilegedHelper.plist (2016-02-08) [Support]

[running] com.fxtech.fxlm.plist (2014-08-01) [Support]

[loaded] com.google.keystone.daemon.plist (2016-08-31) [Support]

[running] com.iobit.AMCDaemon.plist (2016-04-18) [Support]

[not loaded] com.maintain.HideSpotlightMenuBarIcon.plist (2016-10-19)

[loaded] com.oracle.java.Helper-Tool.plist (2016-09-22) [Support]

[running] com.promise.BGPMain_R.plist (2016-02-17) [Support]

[loaded] com.promise.bgasched.plist (2016-02-17) [Support]

[running] com.promise.diskmonitor.plist (2016-02-17) [Support]

[loaded] com.promise.emaild.plist (2016-02-17) [Support]

[loaded] com.rogueamoeba.instanton-agent.plist (2016-01-13) [Support]

User Launch Agents: ⓘ

[loaded] com.adobe.AAM.Updater-1.0.plist (2016-01-25) [Support]

[loaded] com.adobe.ARM.[...].plist (2016-11-07) [Support]

[running] com.disc-soft.DAEMONTools.DAEMONToolsAgent.plist (2016-02-08) [Support]

[not loaded] com.extensions.updater69337.ver (2015-07-15) Adware! [Remove]

[loaded] com.iobit.AMCUpdate.plist (2016-05-22) [Support]

[running] com.iobit.MacBoosterMini.plist (2016-10-24) [Support]

[loaded] uk.co.markallan.clamxav.freshclam.plist (2014-08-21) [Support]

User Login Items: ⓘ

Quicksilver Application (/Applications/Quicksilver.app)

smcFanControl Application (/Applications/smcFanControl.app)

Dropbox Application (/Applications/Dropbox.app)

ClamXavSentry Application (/Applications/02 Anti-Virus/ClamXav.app/Contents/Resources/ClamXavSentry.app)

Activity Monitor Application (/Applications/Utilities/Activity Monitor.app)

Twitter Application (/Applications/Twitter.app)

ClamXavSentry Application (/Applications/02 Anti-Virus/ClamXav.app/Contents/Resources/ClamXavSentry.app)

Wondershare Helper Compact Application (~/Library/Application Support/Helper/Wondershare Helper Compact.app)

Uploader Application (/Applications/Uploader.app)

CrossOver CD Helper Application (/Applications/CrossOver.app/Contents/Resources/CrossOver CD Helper.app)

SPanel Application (/Library/Printers/SPanel/Samsung/SPanel.app)

com.adobe.SwitchBoard.monitor.plist MachInit (/etc/mach_init_per_user.d/com.adobe.SwitchBoard.monitor.plist)

Mach Init items are deprecated

Internet Plug-ins: ⓘ

iPhotoPhotocast: 7.0 - SDK 10.8 (2013-04-20)

FlashPlayer-10.6: 23.0.0.207 - SDK 10.9 (2016-11-08) [Support]

QuickTime Plugin: 7.7.3 (2016-10-26)

Flash Player: 23.0.0.207 - SDK 10.9 (2016-11-08) [Support]

AdobePDFViewer: 10.1.1 (2016-01-24) [Support]

Google Earth Web Plug-in: 7.1 (2015-09-02) [Support]

PepperFlashPlayer: 23.0.0.207 - SDK 10.9 (2016-11-08) [Support]

Silverlight: 4.1.10329.0 (2013-08-01) [Support]

JavaAppletPlugin: Java 8 Update 111 build 14 (2016-10-24) Check version

User internet Plug-ins: ⓘ

BlueStacks Install Detector: Unknown

Safari Extensions: ⓘ

Evernote Web Clipper - Evernote Corp. - http://evernote.com (2015-08-23)

TinEye - Idée Inc. - http://www.tineye.com (2014-01-09)

Video Converter - Wondershare - http://www.wondershare.com (2014-03-19)

Audio Plug-ins: ⓘ

EcammAudioLoader: 1.0.4 - SDK 10.11 (2016-03-26) [Support]

CallRecorder: v2.5.20 - SDK 10.11 (2016-03-26) [Support]

3rd Party Preference Panes: ⓘ

Flash Player (2016-10-25) [Support]

Java (2016-10-24) [Support]

MacFUSE (2008-12-19) [Support]

Time Machine: ⓘ

Skip System Files: NO

Mobile backups: OFF

Auto backup: YES

Volumes being backed up:

Macintosh HD: Disk size: 998.97 GB Disk used: 698.01 GB

Destinations:

Midwest Big [Local]

Total size: 3.00 TB

Total number of backups: 87

Oldest backup: 31/8/15, 23:40

Last backup: 15/11/16, 19:40

Size of backup disk: Excellent

Backup size 3.00 TB > (Disk size 998.97 GB X 3)

Top Processes by CPU: ⓘ

6% InstaTab for Instagram

5% WindowServer

2% kernel_task

1% Wondershare Video Converter Ultimate

1% com.apple.WebKit.WebContent(71)

Top Processes by Memory: ⓘ

8.70 GB com.apple.WebKit.WebContent(71)

1.15 GB kernel_task

606 MB Safari

426 MB clamd

377 MB Wondershare Video Converter Ultimate

Virtual Memory Information: ⓘ

2.61 GB Available RAM

43 MB Free RAM

13.39 GB Used RAM

2.56 GB Cached files

0 B Swap Used

Diagnostics Information: ⓘ

Nov 15, 2016, 08:44:49 PM Self test - passed

Nov 15, 2016, 05:35:18 AM /Library/Logs/DiagnosticReports/Final Cut Pro_2016-11-15-053518_[redacted].hang

/Applications/Final Cut Pro.app/Contents/MacOS/Final Cut Pro

Nov 14, 2016, 07:58:08 AM ~/Library/Logs/DiagnosticReports/ProMSRendererTool_2016-11-14-075808_[redacted] .crash

/Applications/Final Cut Pro.app/Contents/Frameworks/Flexo.framework/Versions/A/Resources/ProMSRendererT ool

Nov 14, 2016, 05:37:01 AM /Library/Logs/DiagnosticReports/softwareupdated_2016-11-14-053701_[redacted].cp u_resource.diag [Details]

/System/Library/CoreServices/Software Update.app/Contents/Resources/softwareupdated

Nov 13, 2016, 06:13:20 PM /Library/Logs/DiagnosticReports/com.apple.WebKit.WebContent_2016-11-13-181320_[ redacted].cpu_resource.diag [Details]

/System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.We bKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent

Let's address the items in report colored red first. Since the problem happened in a new User, cleaning up these should allow you to setup correctly in a new User just to verify we have all issues at base level fixed.

Note: you have a lot of really old files. You might find that doing a clean install will give you better results and be faster than trying to find all the bits and pieces that are causing you problems.

There are three Library folders:

Macintosh HD Root folders

Applications

Library <-- root library

System > Library

Users > You > Library

In your root Library....

1) Scroll down to Startup Items folder. Delete these items.

Also in Applications delete the HDD Fan Control app.

Startup Items: ⓘ

HDDFanControlDaemon: Path: /Library/StartupItems/HDDFanControlDaemon

Startup items no longer function in OS X Yosemite or later <------------

2) These files usually block a connection. I suspect they might be coming from Little Snitch. It's possible they are contributing to you being able to connect to your email servers. I would delete.

Configuration files: ⓘ

/etc/sysctl.conf - File exists but not expected

/etc/hosts - Count: 15

3) Find Launch Daemons folder in root Library. Delete all items

4) System Preferences > Users & Groups

Delete all Login items for apps we have removed.

For testing, I would remove all just as a precaution.

5) Remove any antivirus software (AVG, ClamX)

6) Remove SwitchBoard Monitor

com.adobe.SwitchBoard.monitor.plist MachInit (/etc/mach_init_per_user.d/com.adobe.SwitchBoard.monitor.plist)

Mach Init items are deprecated <-----------------

7) You have adware, download and runadware removal tool. Previously named Adware Medic .

Malwarebytes Anti-Malware (free)

https://www.malwarebytes.org/antimalware/mac/

Can't tell you how long I have been working on - no messages in my sent mail. This worked...Yahoo!!! and THANK YOU!!!