OJS 3.0 Notification emails not sent


#1

I have issue in sending the notification emails.
Like when a user register, no welcome mail sent.
When paper is submitted by author, no acknowledgement email sent.
When assign reviewer, no email is sent.

But when I looked up into pHpMyAdmin the email logs shows the entry of all notification emails.

In error log I found the following error occurs when I tried to submit a new article:
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of CustomBlockPlugin::getSeq() should be compatible with BlockPlugin::getSeq($contextId = NULL) in /home/naeemijr/public_html/gnpublication.org/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 129
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of CustomBlockPlugin::getBlockContext() should be compatible with BlockPlugin::getBlockContext($contextId = NULL) in /home/naeemijr/public_html/gnpublication.org/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 129
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of CustomBlockPlugin::getEnabled() should be compatible with BlockPlugin::getEnabled($contextId = NULL) in /home/naeemijr/public_html/gnpublication.org/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 129
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of CustomBlockPlugin::getContents() should be compatible with BlockPlugin::getContents($templateMgr, $request = NULL) in /home/naeemijr/public_html/gnpublication.org/plugins/generic/customBlockManager/CustomBlockPlugin.inc.php on line 129
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of ArticleHandler::initialize() should be compatible with PKPHandler::initialize($request) in /home/naeemijr/public_html/gnpublication.org/pages/article/ArticleHandler.inc.php on line 389
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of SubmissionFileDAO::fromRow() should be compatible with PKPSubmissionFileDAO::fromRow($row, $fileImplementation) in /home/naeemijr/public_html/gnpublication.org/classes/article/SubmissionFileDAO.inc.php on line 23
[14-Jul-2018 08:32:58 UTC] PHP Strict Standards: Declaration of SubmissionKeywordEntryDAO::getByControlledVocabId() should be compatible with ControlledVocabEntryDAO::getByControlledVocabId($controlledVocabId, $rangeInfo = NULL, $filter = NULL) in /home/naeemijr/public_html/gnpublication.org/lib/pkp/classes/submission/SubmissionKeywordEntryDAO.inc.php on line 20
[14-Jul-2018 08:32:58 UTC] PHP Deprecated: Non-static method PKPRequest::getBaseUrl() should not be called statically, assuming $this from incompatible context in /home/naeemijr/public_html/gnpublication.org/lib/pkp/plugins/generic/usageStats/PKPUsageStatsPlugin.inc.php on line 434
[14-Jul-2018 08:32:58 UTC] PHP Deprecated: Non-static method PKPRequest::_checkThis() should not be called statically, assuming $this from incompatible context in /home/naeemijr/public_html/gnpublication.org/lib/pkp/classes/core/PKPRequest.inc.php on line 158
[14-Jul-2018 08:32:58 UTC] PHP Deprecated: Non-static method PKPRequest::getBaseUrl() should not be called statically, assuming $this from incompatible context in /home/naeemijr/public_html/gnpublication.org/plugins/generic/shariff/ShariffPlugin.inc.php on line 130
[14-Jul-2018 08:32:58 UTC] PHP Deprecated: Non-static method PKPRequest::_checkThis() should not be called statically, assuming $this from incompatible context in /home/naeemijr/public_html/gnpublication.org/lib/pkp/classes/core/PKPRequest.inc.php on line 158