[horde] Problem sending mail (active sync) with stack trace

[r.j.baart at prompt.nl]

Note: Added the stack trace

Hi,

Sending mail always worked correctly. But since today and I don't know 
why but I can't send messages through active sync. I think following 
lines indicates the problem:


2020-09-02T15:09:13+02:00 EMERG: HORDE Error: Call to undefined function 
_getSmartPlainText() in /usr/share/php/Horde/Core/ActiveSync/Mail.php:489

Stack trace:
#0 /usr/share/php/Horde/Core/ActiveSync/Mail.php(418): 
Horde_Core_ActiveSync_Mail->_getPlainPart('1', Object(Horde_Mime_Part), 
Array, Object(Horde_Mime_Pa
rt))
#1 /usr/share/php/Horde/Core/ActiveSync/Mail.php(382): 
Horde_Core_ActiveSync_Mail->_buildSmartReply()
#2 /usr/share/php/Horde/Core/ActiveSync/Mail.php(258): 
Horde_Core_ActiveSync_Mail->_sendSmart()
#3 /usr/share/php/Horde/Core/ActiveSync/Driver.php(2256): 
Horde_Core_ActiveSync_Mail->send()
#4 /usr/share/php/Horde/ActiveSync/Request/SendMail.php(106): 
Horde_Core_ActiveSync_Driver->sendMail(NULL, false, true, NULL, true, 
Object(Horde_ActiveSyn
c_Message_SendMail))
#5 /usr/share/php/Horde/ActiveSync/Request/SmartReply.php(44): 
Horde_ActiveSync_Request_SendMail->_handleWbxmlRequest()
#6 /usr/share/php/Horde/ActiveSync/Request/Base.php(250): 
Horde_ActiveSync_Request_SmartReply->_handle()
#7 /usr/share/php/Horde/ActiveSync.php(833): 
Horde_ActiveSync_Request_Base->handle()
#8 /usr/share/php/Horde/Rpc/ActiveSync.php(144): 
Horde_ActiveSync->handleRequest('SmartReply', 'ANDROIDCxxxx...')
#9 /home/xxx/yyye/rpc.php(160): Horde_Rpc_ActiveSync->getResponse(NULL)
#10 {main} [pid 2863390 on line 74 of 
"/usr/share/php/Horde/ErrorHandler.php"]

Someone any idea what the problem is?

System: Debian buster + backports, php 7.3, all modules up-to-date.

-- 

Cordialement,


R.J. Baart