Website crashed

I just installed your smtp plugin and the website has crashed.
here is the error………….
FROMwp_wfblocks7WHEREtypeIN (7) AND (expiration= 0 ORexpiration> UNIX_TIMESTAMP()) ORDER BYtypeSortASC,id` DESC made by wfWAFIPBlocksController::synchronizeConfigSettings, wfBlock::lockouts, wfBlock::allBlocks, QM_DB->query
[11-Jun-2021 00:37:08 UTC] PHP Warning: Illegal string offset ‘to’ in /home/buyatestkit/public_html/wp-content/plugins/post-smtp/Postman/Phpmailer/PostsmtpMailer.php on line 71
[11-Jun-2021 00:37:08 UTC] PHP Warning: Illegal string offset ‘subject’ in /home/buyatestkit/public_html/wp-content/plugins/post-smtp/Postman/Phpmailer/PostsmtpMailer.php on line 72
[11-Jun-2021 00:37:08 UTC] PHP Warning: Illegal string offset ‘message’ in /home/buyatestkit/public_html/wp-content/plugins/post-smtp/Postman/Phpmailer/PostsmtpMailer.php on line 73
[11-Jun-2021 00:37:08 UTC] PHP Warning: Illegal string offset ‘headers’ in /home/buyatestkit/public_html/wp-content/plugins/post-smtp/Postman/Phpmailer/PostsmtpMailer.php on line 74`

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