Python email sends the recipient to the configuration file to report an error

configuration file
[mailreceivers]
who= ["XXX@XXX"]

msg_to=config.get ("mailreceivers"," who") is used in the program. The message failed to be sent after running. The exception error is
message delivery failure (503, bounded error: need RCPT command")

I printed the value of msg_to in the middle, which is ["XXX@XXX"], and there is no problem with running msg_to= [" XXX@XXX"] between configuration files. Do you know the solution?
there is no problem with ps: mailbox settings

Mar.29,2021

you should separate the receiving address with a comma

[mailreceivers]
who=a1@example.com, a2@example.com

is then converted to a string array after reading

raw_value = config.get('mailreceivers', 'who')
msg_to = [i.strip() for i in raw_value.split(',')]
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1bf2a89-31e33.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1bf2a89-31e33.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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